Most Helpful Guy
While I usually am in the camp of bluntly asking that doesn't mean there's no way to find out in a more subtle way. Study her behaviour around others - without constantly staring at her, that is. Then contrast it with her behaviour around you. Does she act more nervously, does she do certain things (biting her lip comes to mind) that usually portray nervousness? Does she alter her behaviour in another way - does she act more openly or does she act coldly, does she change the pitch of her voice, the stance of her body, do her muscles relax or do they tense up? These are all things to look for, they can give a lot of insight. Of course, this list is by God not exhaustive.
Most Helpful Girl
You can pay attention to small details. For example, does she bite her lips or look at your lips while talking? Does she find an excuse to touch you or does she look at you a lot when she thinks you’re not watching? These might be signs she likes you