I am lying in bed with my back towards the younger. She is rather tenderly tickling my lower back.

“What are these?” she asks, touching my hip just below my waist. I turn my head.

“Oh, those are stretch marks,” I say.

“What are they?” she asks.

“They’re marks you get when your skin has to stretch a lot – like when you’re pregnant, that’s when I got those ones.”

“Does everyone get them?” the younger asks.

This is the point in the conversation where I, somewhat depressingly, misread her tone of intense interest as expressing anxiety.

“No, not everyone gets them. So you might not get them [here I am misguidedly, as it will turn out, trying to reassure her] if you have a baby when you’re grown up.”

“Do you only get them when you have a baby?”

“Mmmm … no … it could be at another time when your body grows a lot. Like I got some also when I was a teenager and my body was growing a lot.”

“Can children get them?”

“Mmmm.” I consider.“I don’t think so? But maybe if you grow a lot very fast?”

The younger thinks for a moment.

“I AM having a baby when I grow up,” she declares emphatically. I am surprised by this announcement because she has frequently declared the opposite.

“You are?” I ask, still not cottoning on to what she really means.

“Yes!” she insists, “so I can have stretch marks!”

“Ha! Well … I don’t know that I’d recommend having a baby just for the stretch marks,” I remark drily.

I go off to put on the coffee and when I come back the younger is on the bed in what I believe in yoga is called dolphin pose: like downward dog except that you’re balanced on your head.

“Ow” she says.

“Hmm, that looks uncomfortable,” I say.

“I’m making stretch marks,” she says.

“Oh! No sweets, you can’t make them just by stretching!”

“But it REALLY HURTS,” she says.

“Sweetheart, stop doing it then!”

She blithely ignores me.