I have bought several brands but these are my favorites, at least for my child. My daughter is very tall and thin for her age. She's almost 6 years old and has been weighing 40-42 pounds all year - just getting taller, not wider. They fit her perfectly but she is very slim. I would say the size is more than one size for a normal weight child than more for a child that age. I won't pay full price when there are so many brands to choose from.
Shamrock Girls' Summer Sleeve Shirts - Girls' Clothing and Tops, Tees & Blouses
44 Review
Adorable TABNIX Toddler Little Girlsβ Short Sleeve T-Shirts: 4-Pack Graphic Cotton Tops for Size 2-7 Years
44 Review
Kid Nation Short Sleeve Crew Neck Heather Girls' Clothing for Tops, Tees & Blouses
52 Review
Spotted Zebra Girls' Short-Sleeve Flutter T-Shirts: Amazon Brand for Fashionable Kids
43 Review