Does this mean she's interested?

[Sam]

I go to college and I met a girl recently. I am friends with her roommate and just passed by their room to say "hi." As I was walking her roommate stops me and says "wait, I haven't met you yet." She walked right up to the door way and we talked for about a minute. Then I had to go. I saw her two other times on campus. Both times she said hi to me but she looks really happy and excited to see me. Also after our first convo that was literally a minute she added me on Facebook the following day. This is all of the interaction I've had with her so far.

There was one weird thing though. We were sitting outside somewhere and some of her guy friends were teasing her about calling her boyfriend. She was just laughing about it. On Facebook though it says she's single on her profile.

What do you think? Thanks