Depends on the amount of work. If it involved watching the kids an hour or two a day while she ran to the store and maybe an hour or two of cleaning per day (call it 3.5hr/day or 140hr/month), that would be $1680/mo at $12/hr.
Depending on the area, room could easily be “worth” $1200/mo, with food, use of car, etc, she was being “paid” $1680/mo tax-free. Especially if she had other pension income, having all major expenses handled doesn’t seem like a bad deal for her.
I don’t consider the family to be bad actors. Yeah, yeah, the state of CA would rather get taxes than have people barter, but I don’t consider that a moral question.