I’ve never noticed the father-daughter trio get on the bus. They must board at an earlier stop, the girls decked out in pink—sneakers, hair ribbons and backpacks—and Dad looking as though he’d welcome a cup of coffee. For each of the last three Saturday mornings, though, I’ve noticed them get off the bus. Theirs is the 68th Street stop, where Mom’s already waiting, sitting patiently on a wooden bench in front of Memorial Sloan-Kettering. Alighting from the bus, one daughter runs to her; the other hangs back with Dad, approaching more slowly. Before the scene ends, the bus pulls away from the curb. When it’s over, I hope Dad goes to get that cup of coffee.