And as I sat on that floor holding my sleeping children, I made myself a promise, silently, that has governed every day since: that Lily would never, ever again be handed a weight that was not hers to hold.

She had carried the unbearable, alone, for four hours.

She was done carrying things alone.

That was my job now, and I would not fail it.

And I have thought, since, about what it actually means to make a promise like that, because it is easy to say and hard to live, and the living of it is the whole of what being a parent turned out to be.

It does not mean doing everything for a child, or shielding her from every difficulty; a child who is never allowed to struggle at all grows up weak, and I did not want that for Lily either.