Seated on the ottoman of a plush leather chair in the sitting room that I rarely used, my feet planted, knees spread, the fist of one hand held tightly by the other, and my jaw clenched, I reminded myself again this raving lunatic in front of me was my mother and deserved a semblance of respect. That was all she deserved—the appearance of it—and she was losing that license by the second.

With her skinny arms alternating from waving to slapping her sides, she’d ...