No matter how a contract is written an individual can not surrender there right to sue for tort damages (i.e. anything they may up as harm) but like Smokey alluded to, that doesn't mean they can win or have a case with substantial merit.
As long as the contract details her free willingness and active participation, and there we're no questionable factors affecting here participatory judgement such as drugs drink or forceful coercion during shoots you should come out ok.
