Confusion. Please help!

Ok so here's the deal, I'm 16 and pretty sure I'm a lesbian. I've told a couple of friends that I'm bisexual and they were very supportive, but it's just hard to talk to completely straight girls about stuff. No one else knows or would even suspect anything b/c I'm very girly and flirt with guys. Here's the problem.. I have a crush on a girl that is a year younger than me. She just ended a relationship with her boyfriend of almost 2 years. The thing is, is that she flirts with me a lot. She would jokingly smack my butt and at a party not long ago she let her arm rest on my leg. A few days ago she made a joke to me about how she's "Sick of boys and she's just going to be gay". There are a few other instances where I have gotten a gay vibe from her, but I can't decide if she is really feeling me or if it's all in my head. Does anyone have any advice on how I can make a move without her freaking out? What do you think about the situation?

 

If you think its true..then it's prob true!