Too Excited, Maybe?
You have to appreciate her enthusiasm, even if it doesn’t seem in sync with her team’s performance. In cheerleading, facial expressions are also a crucial part of the routine. Looking relaxed and happy has a positive effect on the audience and makes the performance more entertaining.
This girl seems to have gotten so caught up with the intensity of their routine, which is not necessarily a bad thing. Her friend to the right appears to be struggling, though, and you can’t blame her. Cheerleading is not for the faint-hearted!