These tights seem to be of good quality but I think it would be better to separate the sizes. They are a few inches longer for my 6 month old who fits perfectly into a traditional sized outfit (ie wears 3-6m clothes at this age).
Hollhoff Gymnastics Playgrounds Shorts - Breathable Clothing for Girls
48 Review
Thermajane Girl's Cozy and Comfy Thermal Underwear Long Johns Set with Fleece Lining
46 Review
Tommy Hilfiger Girls Crop White Girls' Clothing
54 Review
C9 Champion Girls Supersoft Bright Girls' Clothing and Active
46 Review