This is my viewpoint:
When watching that video I, as I'm sure most people, wished that they could step in and help that lady out. Probably by getting those kids away from her by any means (mine would have been violence). I'm sure most people felt helpless.
When the opportunity came that they could do something that would be positive towards the woman, people jumped on it. Probably hoping that their donation would help her get away from those kids, either from a vacation or having enough to retire.
I have no problem with her keeping every dime of what she gets. If I donated, it would be in the wish that she does whatever she wants to make herself happy. Let's be honest, any of those "anti-bullying" groups or funds, and these bullying "teams" are a joke anyways. If I had any wish for her to donate, it would be towards a lobbyist that would fight to allow teachers to hit kids again.