I am trying to remember. I think she is level 8 or 9 when you get her back, but not certain. I had Nalia in my party, left her in the Asylum. And as I recall, I don't remember it hurting me any. And my party was high level at the time. And Imoen is a way better thief than Nalia.
------------------
Reeka--The Hand of Death O_H_F
Lady in Waiting (found what I was waiting for)
Official Party Planner and Events Coordinator of the Moon's Hope Inn
Proud Member of the Ladies Guild
GMDLM
