I agree with AnotherStander, she's not BS'ing you. I think she is trying to figure out who she is and what she wants in life, and she's very comfortable with you and values your presence/opinion. That doesn't mean she wants a relationship with you. Maybe in the future, but I just think she sounds confused about her life in general. It sounds like her bringing up sexual history is very confusing for you. My STBXW and I are friends and if we didn't make it a boundary we won't cross, she could easily talk to me about sexual stuff the way you two seem to be doing. It's happened before with us, but we decided that was definitely a boundary we can't cross. If you want to be her friend, stick around and see what happens with no expectations. If you don't want a friend, but you would want a relationship let her know. But in my opinion, she doesn't know what she wants.
Married: 9, Together: 16 Me:33, W:34, D:6, S:3 BD: 1/1/18 EA confirmed: 2/7/18 I moved out 6/1/18