Resistant family member. Any advice?

Good points, Glad. This whole set-up smells bad to me. They will want free care or next to nothing payment and will expect any hours they want. Anytime they want them. That's when or if they actually give over any payment at all.
It's not a good idea to work for friends or family. It really isn't when it involves caregiving for seniors or childcare. Bottom line is strangers often try to take advantage of the person providing these services. When it's friends or family, two hours a day turns into five, that turns into ten, that turns into we need to drop mom or the kids off at your place because we're going on vacation.
They won't pay either. I worked for a friend's family years ago. This experience ended our friendship and she was my best friend since we were kids. We haven't spoken in over 14 years. The job for her grandmother who was a nasty, horrible, disgusting woman. She lived on the first floor with her son and DIL. My friend and her boyfriend at the time lived on the second floor. The hours, days, and pay were agreed upon in advance.
A couple weeks in the tardiness started. Someone would need to stop off at the grocery store, or had an appointment, or had to run an errand (her parents still worked), or needed to go to the gym to let off some stress. Or stopped off for a drink after work. A few times I even saw my friend or her boyfriend pull in the driveway (late) and head straight upstairs to their place. I didn't care about extra pay because I didn't want extra hours. I all but had to pull teeth to get my regular pay. I was only helping them out for a few weeks as a favor until the grandmother was placed and I gave them a special price. After six weeks I asked when she was going. The answer was the facility didn't have a bed yet. That was a lie. This arrangment was working better and cheaper than placing her. It was also protecting assets.
The Wednesday before Thanksgiving they all secretly left from their jobs to the sister's house. Assuming that I'd watch grandma over the holiday (because I worked for them on weekdays) or I'd take her with me wherever I was going. I waited a few hours and called the sister who said no one was at her house. I called the cops and told them the family went missing. They vanished and I couldn't reach them. The cops came with APS and I gave them the family contact info. I locked up the house and grandma went with APS. The police were able to get in touch. They were all up at the sister's house, one state over. They never spoke to me again. I tried reaching out over the years, but for nothing. They never got over it. This is what happens when people agree to caregiving work for family or friends. They take advantage. It's ends relationships. It breaks up friendships, marriages, and families. Don't do it.