What is she thinking? What do you make of this situation?

Last year I had (and still have) a crush on my friend. I asked her to prom but said "as friends" uming she wouldn't want a relationship with me. She gave me what in my opinion was a bad excuse (she said I was too young (I was 14 and a junior in HS, I skipped 2 grades in elementary school)) and she went alone. This year she's a freshman in college and offered to go to my prom with me (but did NOT stipulate "just friends"). I accepted and figured that she was "deterred" when I asked her because I said "just friends" and she actually did want more. A few days ago she was talking about a "cute guy" she knows and then her facebook listed her as "in a relationship" with him. Two days later it listed her as "single". Did something go wrong between the two of them (I don't want to ask because it would seem somewhat stalkerish to know her relationship status changed for 2 days)? Does she just like him as a friend and this was just them fooling around? So was my theory wrong and she really just wants to go as friends? She's been very flirtatious whenever she talks so I don't think this is the case but what do I know about relationships.... Please help!!! I'm so confused....