Genevieve Sandrine du Pointe du Lac Dieudonné
A character of a series of books written in the ye olde days of WHFB, by Jack Yeovil, more widely known as the film critic/horror buff Kim Newman. A very old (older than most adult elves) Wuxia French Kung Fu master barmaid vampiress. I swear I'm not making this shit up.
The Legend
A long time ago, in Parravon there lived a young Bretonnian (French) girl who lived in luxury along with the rest of her family. This was due to her father who was a servant to the local knightly lord. Then a big meanie invaded, killing fuckloads of people and executing all the nobles while plundering the province. Poor little Genevieve's parents were killed and she and her sisters were forced to live under the care of their uncle in the mostly depopulated dukedom until at the age of 16 a pedovampire named Chandagnac found her and made her one of his wives. Chandagnac himself was a servant to Lady Melissa d'Acques, a very prestigious cougar of the Lahmian Bloodline despite looking like a small prepubescent girl of 12. In retrospect, given his taste for young girls, this might explain how Chandagnac became a vampire himself as he might have put the moves on what he thought was an innocent nubile girl only to discover she was really an ancient vampire.
In any event, shortly after transforming Genevieve with the Dark kiss Chandagnac was hunted down by priests of Ulric who sawed his head off with a silver plated scimitar, as he was far too dim-witted and far too eccentric to stay hidden. Genevieve's sisters meanwhile who had not been transformed into a vampire would end up growing old and dying. Left with nobody in the world and with a severe bloodlust and superhuman powers, Genevieve went east.
She spent some time in Araby (the Middle East), during the crusades between them and her people. Eventually, she proceeded through the Warhammer Silk Road and ended up in Cathay, AKA Warhammer China. She became a trader between Cathay and Nippon (Japan), making her one of the few beings to have ever been to Nippon.
At some point, she met a master monk named Master Po (showing GW being creative as always). She ends up spending thirty years with him learning to control her blood lust to the point she required very little to survive and both telling stories to him, as well as learning quite a bit about the cultures Cathay has met. Eventually, Master Po went on to teach important Cathayan generals, but that's not important at all since GW has never bothered making Cathay relevant.
Genevieve traveled to the Empire soon after, where she came out of the closet as a vampire. Somehow this was acceptable in her case, and she mingled in high society until she became bored and frustrated with the pompous nobility (Magnus the Pious, one of the greatest Emperors of the Empire, feeling her up as a greeting probably contributed). She slipped into the lower class, and ended up working as a barmaid in Altdorf in a bar called the Crescent Moon for several decades. During this time, she helped catch a Jack The Ripper style figure and became even more disillusioned by the arrogant and childish nobles.
Eventually, she was found by the teenage Grand Prince Oswald von Konigswald the son of the Elector Count of Ostland who paid her to join him and his crew in their quest to kill Drachenfels. After losing a few friends along the way and fighting past all the greenskins/Daemons/Undead allied to the big baddy she Oswald and the Dwarf Menesh reached Drach's throneroom where Drach proceeded to tear Menesh's arm off (he survived though) and sicked a whole crapload of evil spirits on Genevieve leaving Oswald to fight and apparently kill Drach alone using one of the great Enchanter's trophies, an ancient sword that had Sigmar's dried blood on it.
After their victory, Genevieve returned to her inn and purchased it.
Decades later, Oswald invited her along with her surviving battle buddies and the highest nobility of the time to a play about "his" defeat of Drachenfels to be held at the Great Enchanter's Castle no less. There she met Karl Franz, whom she took a liking to, and the actress playing her, whom she very much hated. She also found herself attracted to the play's director and main actor Detlef Sierck who had been hired on by Oswald in exchange for Oswald wiping out Detlef's massive debt from an earlier botched production he had been unable to finish.
Unfortunately, it turned out the whole thing was an elaborate trap. Years earlier Drachenfels' knowing his latest physical body was decaying had struck a deal with Oswald where he agreed to spare the whimpering teen in exchange for him serving him. Oswald had agreed and Drach had faked his own destruction making Oswald a hero and allowing him to lure all the major players in the Empire to the Enchanter's castle where Drach intended to resurrect and kill off all the leadership in the Empire minus Oswald who would serve as his puppet ruler. Once all the players were in place Drach began to resurrect during the play using a body Frankensteined out of the body of the actor playing him (who was in on the whole mess as well) combined with the body parts of Genevieve's friends who Drach had secretly arranged to be killed off in the leadup to the play. Drach was about to kill Genevieve to finish his resurrection but fortunately, at the last minute, Genevieve went full vampire blood rage and attacked Drach damaging his body enough that it allowed Detlef to getaway. Detlef then grabbed a sledgehammer that one of the stagehands had left lying around and came back swinging to protect his vampire lover. Normally this attack would have done jack-all to the enchanter but as it happens Sigmar had apparently been watching the whole mess unfold and decided to channel his power through Detlef which allowed him to cave the 15,000-year-old bastard's head in and stop his still incomplete resurrection cold.
After the defeat of Drachenfels, Detlef then killed the traitorous Oswald with a sword after the latter botched an attempt to assassinate Karl Franz and his son. With that problem taken care of and hid debt wiped clean courtesy of a greatful Empire Genevieve and Detlef would end up getting married presumably with the Emperor's blessing as otherwise, it can be assumed, the local priests and/or inquisition probably would have raised an objection to the matter.
They returned to her inn, where he continued to write plays known the world over from Ulthuan to Lustria (who knew the Slann were patrons of the arts? (More likely it was referring to the human settlements there such as the town of Skeggi). She bankrolled his productions before eventually leaving him in his late 50s. Detlef never got over her and ended up writing a series of Sonnets about her that were widely considered some of his best work but which were ultimately suppressed by the Inquisition who were probably still salty about his marriage to an undead foreigner.
End Times
Later it was revealed that Drachenfels, as it turns out, did not die. During the End Times he appeared but with no memory of who he was. Turns out getting your head caved in with a divinely enhanced hammer when your only halfway resurrected is a good way to end up with a severe case of amnesia. Nagash stumbled across him and recognizing him from an earlier encounter when he had enlisted his aid against the then mortal Sigmar promised to return his memories to him if he serves him as a servant. Fortunately for the undead Bretonnian bar wench, Nagash reneged on his promise, and Drach would find himself put down for good when he made the mistake of possessing a certain very devout Sigmarite priest named Luthor Huss whose faith ultimately managed to seemingly flash fry the spectral bastard out of existence.
Genevieve herself MAY have had a fleeting unnamed cameo in the lorebook End Times: Nagash. One of the short lore pieces goes into detail about a mysterious meeting that Balthasar Gelt has with an unnamed woman cloaked in shadow and who basically feeds him the idea and plans for the Auric Bastion to stop the Chaos invasion. This is later revealed to be the minion of Queen Neferata, the top Lahmian vampire, as the Vampires have a vested interest in the world continuing and not being destroyed.
The kicker is that in this meeting Gelt notes that the unnamed girl sounds like a Bretonnian from Paravon or Montfort, is very young and drinks a ruby liquid from a goblet. She also states she does not like her female master. Considering that Genevieve is a notably free-willed and independent Lahmian Vampire from Parravon and that otherwise, all Lahmians revere Neferata, this seems like a suggestive nod from GW to the audience as to who this woman is, though it looks like coincidental evidence, but pretty cool nonetheless. As to WHY Genevieve may want to work for her progenitor Neferata considering she has ignored more malevolent vampires in the past, she could just have an alignment of interests with her in not wanting to see the world ended or it's her way of serving Nagash so he doesn't set her brain on fire inside her skull (like he did with all Vampires who refused to serve him, such as Zacharias The Everliving) since as a Vampire Genevieve would certainly have felt Nagash's return.
During Karl's ascendance into God Emperorhood during End Times: Archaon, a wave of holy magic radiated through Altdorf and burned away the filth of generations (as well as all daemons and undead). This likely did not include her though as earlier in the book she had been off delivering a message of warning from Neferata to Vlad Von Carstein before telling him she intends to go home which many people took to mean Bretonnia. In her own words: "My time in this world is coming to an end, just as yours is, and I think I would rather meet in my homeland." Even if for some inexplicable reason she had come to see Altdorf as her home she likely survived despite her undead nature, as according to her novels Karl and his son Luitpold were rather fond of her thanks to her actions against Drachenfels.
Canon?
The Drachenfels and Genevieve stories rely on canon that has since been retconned, and any discussion about either will usually start an argument over the canonicity of the story. To get a picture of how retconned it is, the Bretonnia of her stories is modeled on the pre-French revolution version that was written over YEARS ago. The fact she's a very popular character in the Warhammer Fantasy communities, and her books are generally regarded as being very well written makes those discussions particularly heated.
Almost every source cites the fact that Vampires are universally reviled in the Warhammer Fantasy universe, and in the Empire being or working with the Undead is a heresy as grave as working with Chaos. Despite this Genevieve is openly a vampire and mingles throughout Empire society. She only receives unease from others rather than being chased with pitchforks, and the Witch Hunters of the Empire would normally not hesitate to FWIP anyone regardless of their position. For this, the only logical explanation is that she has had the approval of three Emperors, whose authority even the Witch Hunters must obey.
However, the books infer Genevieve's vampirism is an open secret, as she was chased more than once by angry mobs when her vampirism was discovered but managed to sneak away. Furthermore, she had a vampire support group (of other vampires) who let her know if any Witch Hunters were nearby, in which case she'd keep a low profile. It also helped that she only fed on willing people.
Drachenfels himself is full of canon plot holes, but that can be seen and argued on his own page.
The fact that in the End Times event Drachenfels is canon suggests however that Genevieve is as well. Then again, in End Times everything, well, ended.
That being said, it's been shown through Nagash that many Undead survived (at the very least his Mortarchs and their mounts) so she may have persisted into Age of Sigmar as well, and it's not completely impossible she could be a Sigmarine, as even the undead are part of the ranks. Of course, Drach would have as well.
On the Tabletop
Genevieve, thanks to her globe-trotting lifestyle, could be fluffed into most Order armies. Of course Empire and Bretonnia armies work best, as does the player who fields a homemade Cathayan army. For a model the Bretonnian Damsels or the Vampire maidens off the Coven Throne model work best. If using End Times rules, then a wizard in Lore of Undeath works as well.