Since you turned four, our universe has shifted. Small changes in your development that are imperceptible to everyone else are seismic in my eyes. I’ve always noticed the fault lines as I’ve watched you move between the ages and stages of your childhood, gaining new abilities and more independence with each milestone. But the crevice between three and four seems deeper, more defined.

Suddenly, you are completely yourself, full of perception and opinions and surprising vocabulary, and not at all the quiet, pensive baby I held a few short years ago.

Suddenly, the fuzzy little shoulders that I used to smother with kisses are strong and broad, opening the refrigerator, reaching onto countertops, hoisting your body as you bounce along the furniture. When you were three, you needed me to do these things for you—get your milk, grab a snack, help you up. Now that you’re four, you’ve stopped asking.

Now that you’re four, you carry your body with a confidence that I have never seen you exhibit. Your gait is longer and straighter. Gone is the wobbly side-to-side toddler dance. You stand tall. You’re suddenly so tall. And you try things that you never would have attempted, my cautious girl.

Now that you’re four, you’re climbing and flipping and jumping. Never one to take chances before, now that you’re four you’re settling in to yourself. Trusting yourself. As I watch, I see that those years of observing from the sidelines have stayed with you.

I see you assessing the situation, thinking before you try something. But now that you’re four, you try it. And now that you’re four, I find myself trusting you to think and assess and to be cautious when necessary. But I’m still surprised by your courage.

When you were three, you would ask me to stay with you at school. You would hold onto my jacket, pleading. “Just five minutes, Mommy, please.” And when I had to leave, I would watch as your eyes followed me out the door, wide and brimming with tears. When you turned four, we needed to move you to a new school, and suddenly I was the one filled with apprehension.

As we said goodbye to the teachers and friends you had known since you were a baby, I struggled to keep it together and it was me, now, trying to hold back tears, wanting to stay. And when we walked into your new school and a swarm of new faces ran up and circled you, I felt the same torrent of pressure fill my eyes.

I was overwhelmed for you, certain that you’d turn back to me, grab my jacket, and beg to leave. I was overwhelmed, too, because I didn’t know how to leave you in this new place, with all of these new people. And as I was doing everything I could to stay strong for you, to pretend that my heart wasn’t breaking, you turned back to me and smiled and said, “Bye, Mom.”

In that moment, my heart did break as I realized that, for the first time, you really didn’t need me.

You didn’t need me to be sad or worried for you because, now that you’re four, you are more competent than you’ve ever been. As your competence grows, you’ll need me less, and now that you’re four, your days of needing me for most things are coming to an end.

My heart broke as I realized that the 3-year-old you is no longer around, and there were a whole lot of things I truly loved about that 3-year-old.

I loved how she would dance in jerking moves that didn’t at all align with the beat of the music, and how she would have a funny little way of mispronouncing and misusing new words.

I loved that she thought Chili’s restaurants were pepper stores. I loved how she would ask to be sung to every night and how she would walk around the edge of the playground to avoid the bustle of the jungle gym.

I loved how when I looked at her I could still see the face of the baby girl who surprised us when she arrived early and has been full of surprises since, the face I had always known.

Now, you say things like “That’s impressive!” in the right context. You haven’t asked for a bedtime song in months. You’re climbing to the top of the biggest slide on the playground and zipping down with glee, not fear. Your face is changing. It is longer, thinner, full of expression. Instead of seeing glimpses of the baby you were, I see hints of the woman you’ll become.

I'm heartbroken to say goodbye to the little girl I knew. She disappears a little every day, with each new word that you articulate perfectly, with each new letter you learn to write.

But the elements that are essentially you, your love of dancing, your hilarious observations, your absolute refusal to be anything but stubborn when you want your way, your love affair with mac and cheese, they remain.

And as you’re blossoming into your 4-year-old self, I love getting to know who you are now. I love how you embrace your curiosity. I love how you radiate confidence in your words, in your actions, and in yourself. I’m so impressed by you. I’ve learned to cherish you in this moment, in the person you are.

I’m excited, but not in a rush, to see the person you’ll become. And sometimes, at night, right before bed, when the lights are dim and you look up at me from behind the blanket you’ve treasured since you were born, I see you, my sweet girl, looking back at me with the same eyes I watched open four years ago.