When should I ask her out?

There's this girl who I know has been crushing on me for a couple months now, and today my friends told me that she said I was "hot", whilst I was away. I don't believe them while I know it could be right. Thing is that she likes me but I don't and my annoying friends kept shouting her name across the class to ask her out for me, I refused. I don't talk to her, and I'm thinking, do I even like her, because we are class mates, but not friends. I don't want to rush it. Can anyone help, it's going to work or not, and when?