If the VA pays my dad to pay for in-home care, but his wife is power of attorney and handles his affairs, can she keep the money?

Bopbop, I think you're referring to VA's Aid and Attendance program. Was your father a wartime veteran? That money is paid to the vet, and can be used to pay a family member (or anyone) if the family member is doing the caregiving.

My father is not a wartime vet but he still qualified to have home nurses through VA. This was ordered directly by the doctor and coordinated through VA, who paid the home agency per visit for a set number of visits.

Do you know which type of "in home care" the VA is paying for? Sure sounds like Aid and Attendance if it's not being paid directly to a home caregiving agency, and yes, the wife can keep it as long as the vet is being provided for. 

If you don't feel your father is being adequately looked after, you have options, but first I'd like to know if that's the case. Do you feel your dad isn't being cared for adequately? That's a different thing.

For herself? Certainly not! She must use it for what the VA has provided it for.