Adult ancient Asian fantasy themed, female protagonists, quest

[Bethany]

Read book sometime between 1998-2009

Main character is female, is to become leader/chief/something but must complete a quest and be a virgin to inherit

Other female characters include an emperor's concubine figuring out how to get pregnant even though he's super old, and an ex concubine/companion type who tries to commit suicide

There is at least one male adviser/magician with very very long fingernails on one hand (a sign of prominence/importance)

Magic is part of the story

SPOILERS:


Someone in the main character's quest group betrays and rapes her to try and disqualify her from leadership

The ex concubine character is saved by a palace eunuch

[Ayshe]

Ladylord maybe?