Me [15 M] am not sure what to do about my crush [15 F]

I like this girl at school and want to ask her out but I am not sure what she would say. The problem is that at school we have a group of friends, about 15 people of which only 3 know I like her, and if it goes wrong it would be extremely awkward for both me and her to hang out with this group together. What should I do.

tl;dr: I like this girl, I want to ask her out but if it goes wrong it would later be awkward with our mutual friends.