“My house, my rules,” my daughter-in-law said as she took back the spare key, expecting me to stay with the children while she and my son went away for the weekend.

Sunday. “Six weeks,” I said, and she thanked me several times.

The first two weeks were pleasant. I collected the kids from school three afternoons a week, cooked a few dinners, and listened to their accounts of soccer and classroom projects. Claire seemed relieved each time she got home and thanked me for taking something off her list. I believed we were all working toward the same end: a new child-care plan.

One Thursday she arrived after nine. Daniel was at a client dinner, the children were asleep, and I