Suing the site owner might get stuff taken down initially, but in the long and short of it if the model was of legal age and not under duress when she signed, the courts will likely go with the legally binding contract as opposed to some pissed-off dad who's legal-age daughter did something stupid.

Poor girl, now her brother will want to fuck her :P

I've worked lots with younger adult models and it is very important to ensure they understand what the Model Release involves.

A proper model release will require that the model acknowledge that she/he have consulted legal advise and a producer with their shit together will make sure the model *understands* what they are getting into *beforehand*.

Simply having them sign a release and assume their all 'growed up' may be legally permissible, but it leaves a gaping hole for missed expectations and serious emotional issues on either end.

I don't know how old this one was, but expecting considered decisions from younger inexperienced people is naive (regardless of law) and often an exploitive posture - ie. many producers (I'm not suggesting this one) don't really want the model to change her mind so they slide through the release in a perfunctory way.

How much proactive explanation did you do with this model?

Did she just read your paperwork and sign it, or did you underline the seriousness of her commitment?