I'm not sure why all these people keep telling Op's to tell the object of their desire how they feel when he/she hasn't shown you in actions that she cares for you in such a way. That is the worse thing you can do. It will make anyone run when you put them on the spot to confess feelings back when they are not in the position to want those feelings or to reciprocated them.
Take her out to do something fun and move in for a kiss. If she doesn't reciprocate then you know that she's not interested in you in the same way. It's best to find out because you will only stagnate yourself from finding someone who will want you in that way as long as you're following around some girl that doesn't want you like a faithful family pet.
If she doesn't want to be your girlfriend then its best for YOU to Stop being her male-girlfriend as well.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion