Good points, thanks for the feedback. I'm not committed to it yet, so I'll think on it. If I can't find a way to make it work without that problem, I'll drop the idea. .
edit: Maybe I should make it - The faster her opponent moves, the more powerful she becomes. If the other's speed feeds her power like water or air hitting a turbine, it could force her opponents to slow down. Either that, or she gets a powerboost.