The swimsuit is quite beautiful, but as for fit I can't comment. I ordered a size too big for my daughter (2t). I received it, and thought it looked small. I checked the sales tag and it showed 2t. When I tried to out it on my daughter, I'm could barely put it on. I checked the actual tag of the swimsuit, and it was 12 to 18 months.
The suit is very cute but the cut is short. My daughter is a sz 4-5 we got this suit in a 6 in case she had a growth spurt this summer but it barely fits her now. The torso is short and being that the top of the suit narrows, it causes her chest to be exposed.