TnT were the only decent ones I could find for a cheap price - most of the others were wool/polyester, ewww Plus they'll last ages, the only go up to size 1 but my 3yo can still squeeze into them! Congrats, Scarlett is an awesome name
Merino if you want to pay $$, otherwise the wool/nylon mix ones over a cotton singlet are fine. I got mine from Farmers (Teeny Weeny brand) or The Warehouse (Babywise brand) and they have lasted for ages.