a member

So, I have this one friend of mine and just to be clear we're both girls. I always feel this tingly sensation whenever I talk to her, and when she speaks? I feel like the world shuts and focuses on her. I'm straight, I've liked boys in the past so I think I know my sexuality, but what confuses me is why does this sensation only appears when I'm with her? I mean, she's beautiful, kind, smart and gentle with animals, I love her personality, I love the way she smile. I haven't asked my friends about this, neither have I informed them. What do I do? I think I'm falling for her.