She slides into the car, and even before she buckles her seat belt, her phone is alight in her hands. A 13-year-old girl after a day of eighth grade.

She says hello. Her au pair asks, “Ready to go?”

She doesn’t respond, her thumb on Instagram. A Barbara Walters meme is on the screen. She scrolls, and another meme appears. Then another meme, and she closes the app. She opens BuzzFeed. There’s a story about Florida Gov. Rick Scott, which she scrolls past to get to a story about Janet Jackson, then “28 Things You’ll Understand If You’re Both British and American.” She closes it. She opens Instagram. She opens the NBA app. She shuts the screen off. She turns it back on. She opens Spotify. Opens Fitbit. She has 7,427 steps. Opens Instagram again. Opens Snapchat. She watches a sparkly rainbow flow from her friend’s mouth. She watches a YouTube star make pouty faces at the camera. She watches a tutorial on nail art. She feels the bump of the driveway and looks up. They’re home. Twelve minutes have passed.

Katherine Pommerening’s iPhone is the place where all of her friends are always hanging out. So it’s the place where she is, too. She’s on it after it rings to wake her up in the mornings. She’s on it at school, when she can sneak it. She’s on it while her 8-year-old sister, Lila, is building crafts out of beads. She sets it down to play basketball, to skateboard, to watch PG-13 comedies and sometimes to eat dinner, but when she picks it back up, she might have 64 unread messages.

Now she’s on it in the living room of her big house in McLean, Va., while she explains what it’s like to be a 13-year-old today.

“Over 100 likes is good, for me. And comments. You just comment to make a joke or tag someone.”

The best thing is the little notification box, which means someone liked, tagged or followed her on Instagram. She has 604 followers. There are only 25 photos on her page because she deletes most of what she posts. The ones that don’t get enough likes, don’t have good enough lighting or don’t show the coolest moments in her life must be deleted.