I think that the biggest problem with those shoes is when they're worn by younger girls who have a hard time walking in them without tripping. As long as she's a few years into her teens and past that stage where her body is changing and it's hard to keep her ballance, she should be fine.
Kallison, I completely agree that schools should set rules regarding reasonable footware. I used to work with kids, and they were always getting their feet hurt because their parents let them go out in shoes that you really shouldn't wear if you're clumsy or around lots of people. Even clogs without heals in the back can be dangerous for elementary age kids who have recess. They're forever walking or running straight out of the their shoes and then falling.