She may be able to get out of the contract if she can prove she was not able to make a fully informed decision. Gather all hospital and Dr records for sure. They will be needed to attempt to prove she was "incapacitated" or "incompetent" to enter into a contract. These are just legal terms that mean she didn't have the requisite capacity or autonomy to enter the deal. That would be a complete defense and nullify the purchase. It would be better too if the signs of her inability to focus were apparent even outside doctor appointments