Looking over to the girl, Kara frowned and then reached forward with he own hand, trying to still the glass with her strength. Except it was magic, and she knew that magic had something on her. She couldn't always beat it. "If you can't stop it then you had better turn around and get out of here." Because it was way too late to pretend that she didn't know what was going on. People were already starting to look. It didn't take long for people to catch on.
"It's your magic, try again." she said gently, ignoring the fact that the girl seemed startled. Why she would have come in here if she knew she was going to start something like this was beyond Kara. Maybe she didn't know, but there wasn't much Kara could do in this situation except get her to focus.
"Ignore the people. Focus." people were going to gawk at anything, but worrying about other things instead of really concentrating was bound to have some sort of impact on how she was going to get her magic to work, right? Well, it was just a theory, but it made sense in Kara's mind.