And suddenly, everything changed.

Ainsley only just turned 11, and I know adulthood is still years away.

But for the rest of my days, when I look back on the summer of 2013, I will see it as the summer when my little girl grew up.

Some of the changes were physical. We had to go bra shopping and have discussions about how to shave. (Some of you know that I am not the best role model for this, but I'm all she's got. Let the tourniquets begin.)

Others were more subtle. Her sarcasm has become more frequent (and more annoying, because it's generally aimed at me.) She's been a little more moody, a little more dramatic. The first month of summer, all she wanted to do was run and play outside. By the final weeks, all she wanted to do was text her friends and read or watch Harry Potter. Particularly the third movie, which is arguably the one where you realize, "Hey. These kids are no longer kids." How fitting.

Her metamorphosis shouldn't have been surprising. She just started 6th grade, after all, and that is officially middle school. In-Between Land. The horrifying time in a young person's life when she has one foot in the shimmering world of adolescence and the other firmly stuck in the quicksand of teenagery. She's young for her grade, though, and I thought we might get one more year of true, joyful childhood from her before crossing that bridge.

Alas, she outgrew herself right on schedule.

So this Christmas will be the first Christmas that Santa doesn't come. And, she claims, the first Halloween with no tricks or treats. (I can't help but think the lure of chocolate will change her mind.)  For her birthday, the only requested item in the "toy" column was a Magic 8 Ball. The main thing she wanted for her 11th was to have her best friend over to eat pizza and watch a movie.

Goodbye, Chuck E. Cheese. Hello, girls' nights in.

With so much innocence lost, I feel more compelled than ever to cherish those rare moments when I look at her and see the little girl beneath the slimming face, deepening voice, and abandonment of childish things.

One day this summer I checked on her while she was taking a post-swim-practice nap. It's been years since she last napped regularly, but two-a-day swim practices made them a necessity for several weeks this season. In her dark and quiet room, decorated with black curtains and neon-bright peace symbols, I found her curled on her side, holding her precious stuffed elephant tightly under her chin.

In sleep, she wasn't talking back to me. Or rolling her eyes. Or being moodily sarcastic. Her flushed cheeks and deep breathing took me back to her toddler days, when a shared nap was our favorite hour of any summer day. In that moment, she was my sweet little girl again. The one who watched The Goodnight Show on PBS Sprout every night. The one who danced to Wiggles songs and asked me to play Laurie Berkner CDs in the car. The one who wanted to be a different Disney Princess each year for Halloween and who believed wholeheartedly that when you wish upon a star, your dreams come true.

I knew the moment, like childhood, was a fleeting joy. So I did what any nostalgic mom would do.

I gently wiped her damp hair from her forehead. I brought her summer quilt up to cover her chilled knees. I kissed her flushed cheeks.

And then I grabbed my phone to take a picture.

For if I've learned nothing else this summer, I've learned that the sweetest moments of childhood are gone before you know it. Grab them while they last.