Watch her reactions to you, see if she is feeling the same as you. You can also do for her a romantic gesture like a romantic date or get her alone with you so you can talk. I've done that and the girl I was with was more comfortable expressing her feelings witout a large group of other people to put on the spot and it worked. Make her feel like she's the only thing you desire and tell her that you like her and would like to see her more and I think if she likes you she would.