I raised my brother’s 3 orphaned daughters for 15 years — last week, he gave me a sealed envelope I wasn’t supposed to open in front of them.

I sat through school plays and parent-teacher conferences and the specific painful social dramas of middle school, which required a sensitivity I had to develop from scratch because I had not been to middle school in some time and had forgotten the velocity at which friendships could form and collapse and the genuine devastation that accompanied the collapse. I drove to emergency rooms twice, once for Lyra’s broken wrist from a gymnastics accident and once for Dora’s allergic reaction to something in a birthday cake, both times with my heart in my throat and both times with the specific clarity that emerges in emergencies, when you understand without ambiguity what matters and what does not. I helped Jenny with college applications four years in a row. I helped Lyra navigate the complicated emotional terrain of her first serious relationship, which ended badly the way first serious relationships tend to end, and held her on my couch while she cried with the wholehearted investment of someone who has not yet learned to pace her grief.

I did all of this without the word mother attached to any of it, because I was their aunt and that was the accurate word, the one we used, but accuracy is not always the whole story. What I became to them was the thing the word describes more than the word itself: the person who was there, who stayed, who showed up for the next thing and the thing after that, who did not leave.

They became mine. There was no ceremony for this, no single moment when something was officially transferred. It happened the way rivers change course, gradually and then completely, and by the time it was done the original landscape was something you had to work to remember.

The knock at the door came on a Tuesday in late October, late afternoon, the light already failing in the way of autumn light that seems to apologize for leaving early. I almost didn’t answer because we were not expecting anyone, and the afternoon had the settled quality of a weekday that has found its rhythm, the girls home from their various activities, the kitchen beginning to produce the sounds and smells of someone beginning to think about dinner. I opened the door without particular expectation.

He was older. This was the first thing I registered, before recognition, before anything else: this man was older than the man I remembered, which was logical and which my brain had still somehow failed to anticipate. His face had the drawn quality of a person who has spent years carrying something heavy, the weight visible not in any single feature but in the aggregate, in the set of the jaw and the eyes and the way he held his shoulders. He was thinner. His hair had gone mostly gray.

But it was Edwin. There was no question of that.