I have a 10 year old foster child who can still wear size 6 shorts and t-shirts. Eventually he got a little taller but super-duper thin. We're FINALLY down to a size 8 this year, but before that we were a size 7. The Levis slim fit performance jeans are the only ones he'll wear because they're really skinny and he loves the soft fabric their performance line is made of consists . Even size 8 has big elastic bands that reduce the waist, which will help your slim kids. I've searched and searched for strong, slim jeans with regular boots/regular cuts (no skinny jeans) and this is the best I've found.
Boys' Basic Skinny Jeans from The Children's Place
41 Review
π Thermal Blue Thicken Boys' Clothing by FREDD MARSHALL
36 Review
π Essential Straight Fit Jeans for Boys: Top Choice in Amazon's Boys' Clothing Collection
47 Review
Classic Levi's Boys' 505 π Regular Fit Jeans for Everyday Wear
38 Review
Boys' Adidas Active Sports Tricot Athletic Clothing
45 Review
π Bold Pack Sleeve Active Hoodie Sweatshirt Set for Boys' Clothing - Stylish and Comfortable!
47 Review
π Boys' Outdoor Climbing Convertible Trousers - Waterproof | Clothing
47 Review
Arctix Youth Pants Reinforced: Large Boys' Clothing for Active Adventures
46 Review