[Arkan]

Yeah, it's kinda hard to ask a complete stranger out. The odds are against you. You should at least make your presence known before asking her out. Perhaps you should chat with her before so she at least gets to make an opinion about you. Perhaps go there earlier, purchase something and strike up a conversation. Feel her out...if she's receptive, then there's your answewr for later. If everything goes smooth, go back and chat with her some more then ask her to accompany you somewhere (drink, lunch...whatever)

You're not in an easy position....good luck.