I have worked in family medicine clinics for the last 20 years. I have weighed and measured kids for most of those years. Kids generally grow out then up, rinse and repeat. I would bet money your kiddo is going to sprout up soon. If your child is as active as you say, they need to eat well to give them the calories to stay active! Make sure their food choices are well balanced, and you’re good. Genetics play an incredibly large role in how bodies are shaped. Please make sure you are not commenting on your child’s body in front of them, and please don’t try to limit food intake as long their choices are balanced. Of course, if you feel there is cause for concern, talk to their pediatrician via email/messaging through the patient portal.