There are two kids at Sophie’s school with Down syndrome.

Sophie. And another little girl, who happens to be in Sophie’s class. Let’s call her Amelia.

Sophie and Amelia look nothing alike. And yet, of course, they do. Even before Sophie chose wire-rimmed glasses that look a lot like Amelia’s, the similarities were striking, and not just because both girls have straight brown hair. The eyes, the nose, the tongues that slip out — almost 8 years later it still strikes me as incredibly bizarre that a chromosomal abnormality makes people look alike.

Tonight Annabelle, Sophie and I all had our bare feet propped on the coffee table and I was noticing how much different Sophie’s toes look from Annabelle’s and mine. It’s true. It just is.

And yet, Sophie and Amelia look nothing alike. Amelia is tall, she has a different gait and sweet round cheeks. She’s the sar of the monkey bars 365 days a year, while Sophie refuses recess when the temperature’s above 85. (Now, THAT she gets from me.)

You might expect that the two are best friends. Not so much. They hang out — sometimes. Sometimes not. Two completely distinct little girls.

The other day at Brownies, Amelia’s mom told me about an encounter Amelia had on the playground with a school staff member. The staff member — who has been around both girls plenty — kept referring to Amelia as Sophie.

Not cool, the mom and I agreed. Not cool at all. But not entirely surprising, to be honest.

The next day, at ballet, one of my best mom friends and I were chatting about the week’s events, and told her the story. She smiled.

Turns out, Amelia often greets my friend’s daughter, Lily, as Annabelle. Lily and Annabelle look about as alike as — Sophie and Amelia.

“Hey,” I said to Amelia’s mom today, when I told her that story, “maybe we all look the same to them!”

And we cracked up.