It's entirely dependent on the contact that they should have had her sign before hand. Since she claims that she never signed one that allowed for the video to be used, that should be easy to prove either right or wrong.
At which point, the case is pretty easy to decide on from a legal standpoint.
They only paid her $200 bucks? Jesus, 12 year old babysitters make $20/hr these days and they don't have large portions of the internets threatening them. I don't blame her for trying to cash in.
$20/hour isn't bad for what amounts to walking around the streets while somebody films you. It's probably better than what half the people who catcalled her are making, to be honest.