Can you tell me how in detail? I want to turn the handmaiden evil!
Well I could but I don't think there's enough text here to do so...best bet is to go to gamefaqs.com and use the Influence Guide there under Kotor II, that'll really save you some time...
Bottom line- Gaining influence with handmaiden you have to perform good acts in her sight or better yet start dueling with her on the Ebon Hawk, that'll boast her influence with you in no time...on dark side her clothing (including lipstick) will turn jet black...
I won't spoil anything for you but in the end she reveils her real name and such to you...