Look at it this way, if you presume she doesn't like you and don't ask. Then nothing will ever happen and you'll feel rejected any way because you think she doesn't like you even if she does. so that's a situation where you will definitely lose.
However if you ask the girl you like, she might say yes, even if you have doubts. So with this situation you actually have a chance of being with her.
Just ask her man, good luck