“HEY ARE YOU ALMOST DRESSED?” I yelled out from the bathroom one morning last week.

Sophie appeared in the doorway, wearing a tee shirt that said Hopeless Dreamer on the pocket, chewing hard on her well-worn thumb, almost twice the size of a normal thumb from years of sucking. Fifteen years.

“This is what 15 looks like,” I thought, gazing at her for a moment before breaking the reverie for the mad dash out the door to school.

It looks pretty good.

This morning Sophie was up early, at 5:30, ready for presents on her actual birthday. She burst into the kitchen and requested a cup of coffee.

“Now that I’m 15 I will drink coffee,” she said.

I put a lot of milk and sugar in it.

“It’s so weird that I’m 15,” she kept saying, almost to herself.

I get it. It’s weird to me, too. Sophie is caught in that space between child and adult, and I wonder all the time when and if that will end.

Yesterday at the spring ballet recital her moves were (almost) perfectly matched with her classmates, and from far away the biggest giveaway that Sophie is different was her boobs — the rest of the class, a couple years younger, was flat chested. She didn’t seem to notice or care, too focused on remembering the steps.

Sophie’s soundtrack these days is the Avett Brothers, Taylor Swift — and the “Wow Wow Wubbzy” theme song. She got almost every question right on her world history final this morning, I hear, but blew the math. She loves YouTube videos about how to put on makeup and organize your room. She is boy crazy. She has mixed feelings about her bangs. Last week, her dad noted, she used the word “viable” in conversation. Correctly. Last month she wanted to be a choreographer and photographer when she grew up; last night she told us she’d like to be a dancer and a babysitter.

She is, in equal parts, a giant pain in the ass and an absolute joy. About right for 15, no?

There’s another birthday today, the birthday of this blog. I know it’s weird to remember the birthday of a tiny media outlet, but it’s pretty easy to remember that I started Girl in a Party Hat on Sophie’s fifth birthday. Today that girl is 10. I baked her a cake, which Annabelle decorated.

This blog has been such a gift to me. I met some of my favorite people through it, worked out some problems on it, documented highs and lows and, I hope, offered a glimpse of what it means to raise a child with Down syndrome in the 21st Century.

I’ve definitely slowed down on Girl in a Party Hat in recent years, partly because I’ve been busy and sometimes a Facebook status update does the trick, but also because I’ve been holding back as Sophie gets older, and more aware. Sophie loves that I write about her, she always has. Last week she talked me out of three copies of my books, which she signed and gave to three of her high school friends.

“Mom,” she told me recently, “it’s time for you to write a second book, one about my teenage years.”

Not so fast, I told her. “We’ve got several years to go.”

I’m okay with taking our time. At almost 17, Annabelle is entirely too grown up — driving, taking the SAT, wrapping up her junior year of high school.

And so this morning, when Sophie asked for coffee again tomorrow, but in a sippy cup this time instead of a mug, I smiled instead of cringing — and said okay.