Galagirl, in the past I have tried to figure out what she is uncomfortable with and she only gives me vague answers before changing the subject. On the times I have tried to bring things back to the subject at hand she closes down. And them later tells BF that she felt "attacked." We have very different ways of communicating. I'm more the type to put it out there and lets see what we can do, whereas she's more of an "it is getting uncomfortable lets avoid this uncomfortable subject" type.
I know he is very reassuring of her. Almost to the point where I think he coddles her much as one does with a child. She constantly needs reassurance from everyone around her in all aspects, home, friendship, work, etcetera. I've told BF to make sure he pays her extra attention at home. Buying her flowers, taking her on dates and even just sitting on the couch cuddling. And after any time things have happened to make extra sure he is open and supporting of her. It only helps to a small degree. Sometimes she wi briefly talk about what happened. Other times she accuses him of things such as kissing me more than her or saying things that imply he enjoys things more with me than her. This is why I am not comfortable doing things in the same room. She watches BF and I to the point that my DH has told her it's not fair to him because she isn't fully with him. But when we have tried things in separate rooms or even letting the two guys be with her she states she doesn't like it because I'm being left out (though it was my choice).
I'm getting off on a tangent now. But I think I've answered your questions. Thank you again for your input.