How should my mother document expenses and hours for providing in home care to my father if they are divorced?

Since my mother and father are divorced they were married for 50 years and she moved back with him to care for him after his two strokes. she is his only care giver and now needs help with him, he is a Veteran and I just read about the income requirements and monthly expenses. How does she document his in home care expense since she is his caregiver and only moved back to care for him. Does she just put in the amount she would be paid if he hired someone from an agency? Thank you.