Regarding the free care from a grandparent: my own MIL is wonderful (and competent), but I think about the Toby Keith song "As good as I once was". She'll be great for a few days in a row, but the relentless schedule of five days a week would be more than she can manage. It's just...enervating.
And, yes, free services from a family member require plenty of care and feeding. I know of people who make it work. I refuse to judge people who cannot.