4 Snug Bugs

What size should I expect?

my goddaughter is 4T and 5T shirts and pants that I wanted to make a winter coat in size should I spend the winter of 4 / 5 6 / 7 im getting a coat Overmeyer. http://alpinewarehouse.com/catalog/alpine_clothing/ski_snowboard_jackets/girls_jackets/obermeyer_toddler_girls_puffi_down_jacket

Certainly the most important since it is a winter coat. Thus, it will be able to use large bridges and hot and more layers below (if necessary).