My best friend is sending mixed signals?

Hello all, I really need some advice with my best friend. First let me tell you a little about myself and our relationship. I am the complete opposite of my best friend (calling her S for her privacy). She's good at reading between the lines and English and all this creative stuff while I take anything you say literally and only get subtext if it's a sexual innuendo. The only way I can describe our relationship is through a Grey's Anatomt reference. She is my person. I'm Meredith and she is my Cristina. I tell S every single thing that happens in my life and she probably knows me better than I do. She helped me through trying to figure out/accept my sexuality and basically any other problem I have ever had. And as we all know, Cristina is usually the one who gives Meredith advice, concentrates on her career, etc. S is exactly like that and she doesn't talk about herself or her problems that often (and when she does, it's really cryptic and I don't understand it).
Anyways to my problem now I think she's been telling me that she's maybe bi or just not straight (she definitely does have an interest in men, however) but she's unsure or doesn't want to accept it or something. Her family is homophobic (especially her father while her mother could probably learn to accept it) and that's how she was raised so she still might think there's something wrong with this "lifestyle" even though she has many other LGB friends other than me. We were talking about a girl once and she called her hot but quickly told me to forget it. Later she told me it was because she was afraid I was going to ask something.
I just feel really awful about this because I want to help her so much but I don't seem to have the capacity to understand what's going on.

Super long winded, complicated, and probably confusing post but please comment if you know what I should do.

 

I understand completely that I can't force the topic on her so I told her I wasn't going to ask that question unless she wanted me to. I've also reminded her that I'm always here for her and always will be. She is a naturally more private person than I am so she isn't really used to sharing. I'll give her some space and not mention it.

Thank you for your replies!