After returning to New York, Giselle didn’t head straight home; instead, she took her grandmother directly to the city’s premier hospital for an exhaustive neurological evaluation.

The series of tests monopolized much of the day, with results not due until the following morning. With nothing more to be done, Giselle escorted her grandmother back to the comfort of their home.

This time, she had her grandmother stay at the sprawling mansion she shared with Henry, placing her in ...