If you want to have her as legendary lord, use Crynsos' Faction Unlocker. Do not use this mod with that Faction Unlocker.
Crynsos' Faction Unlocker+

This mod adds new unique lord for Empire, Elspeth Von Draken
She has access to the lore of death and she can unlock unique Carmine Dragon mount.

She has 2 unique skills:
Death's Timekeeper which will slow down your enemies and Darkwalker which regens her when she is casting.


There's some lore for you
http://warhammerfantasy.wikia.com/wiki/Elspeth_von_Draken

Recruitment:

- She becomes available for Reikland after 1 turn and she is immortal, ai can also recruit her now.

This mod is not compatible with Mixu's Legendary Lords mod