Anyone used her in a game or as a mission seed?

I think she has the capability of being a really interesting pull and npc in general. Particularly her tie to Desolum's noble court. Lots of chance to put the players in high society trying to appease Lady Desolum's whims concerning her visitor.

She's on my list of NPC's that I want to use at some point in the future, but I haven't as of yet. Is she expounded upon in Forgotten Gods or is that blurb in the core book the extent of the canonical information on her?

Don't know about Forgotten Gods.