With my little sister, less is more. I listen more than I talk, and I try to gage her mood. When she's not feeling well is not a very good time to tell her a bunch of heartfelt crap. "I love you" is dangerous at the best of times. Sometimes she takes it OK, other times she's suspicious of my intentions and says it makes her feel guilty. What works for me best is, I do things with her, things she enjoys. I talk to her about her interests. When everything's relaxed, and we're talking about nintendo or computers or whatever, often the conversation will naturally move in a more serious direction. From what I can tell, just jumping into a serious conversation without warning feels like a confrontation to her. Doesn't matter what my intent is, that's how she sees it. PTSDers don't do well with confrontation. Anyhow good luck, its never easy.