I don't know what type boat she had but if it was a monohull probably half the boats coming out of charter have some keel issues. Usually cracking around the keelboats. If it was a cat there can be similar issues. Not all charter companies dive the hulls after every charter and all boats show some signs of grounding so it can be missed.
It might be possible to get insurance to pay but you normally have to tell them when and how it happened. The real issue is resale value drops on a damaged boat just like a car even if fixed.
G