Hellobee Boards

I have one that's 12-18 months and it looks too small on my average height, 16 month-old. I'd say exchange for a bigger size.

We just bought a 12-18 size puffer from Gap for our LO...she's tiny (3 percentile for height and weight), and it's too big on her, but not too bad considering! The 6-12 fit her better, but we figured we'd get the bigger one anyways.

I don't think Gap runs big, AND it seems that their cotton clothes shrink quite a lot. I bought DS the puffy coat in 4T for this winter and it is a little big on him now (he'll be 3 in 3 months!), but I think it will work the whole winter. 3T would have been risking having to get a new coat in the middle of winter. (DS is on the taller/heavier side though).

Your DD will probably be fine in 3T for the beginning of next winter, and if it's a similar coat to what I found for DS, it's a really nice quality, good looking coat.