What is the way to help a wife endure the continuous abuse from her disabled husband, and does this affect her reward with Allah?

The husband's right over his wife is immense. If it were permissible for a human to prostrate to another human, the woman would be commanded to prostrate to her husband. She cannot fulfill his right completely, no matter how much she serves him. What the mother does in caring for her husband is part of this great right, and she must be patient in caring for him and treating him well, for he is her paradise and her hell. If she dies while her husband is pleased with her, she will enter Paradise. What afflicts the husband, such as dementia or a change in character, will not hold her accountable if she fulfills her duties. Any harm she experiences might be from Satan, so she must fight it with patience. The father should be advised with wisdom and gentleness.