I've seen a few reviews of shirts that are oversized but fit great. My daughter is 4 and the 4T are a bit big but she is small. The adult environment fits as expected. The shirts were also of good quality.
Kid Nation Short Sleeve Crew Neck Heather Girls' Clothing for Tops, Tees & Blouses
52 Review
Adorable TABNIX Toddler Little Girlsβ Short Sleeve T-Shirts: 4-Pack Graphic Cotton Tops for Size 2-7 Years
44 Review
Amazon Brand Sleeveless Chambray Multi Dots Girls' Clothing
62 Review
Girls' Clothing: Spotted Zebra π§ Toddler Long Sleeve Tops, Tees & Blouses
49 Review