This outfit is very cute and the flip flops are a nice touch. It does run small. I bought a 6 for my daughter thinking that it would allow room for her to grow since she usually fits perfectly in a 5. I probably could have ordered a 7. Even though the outfit runs small, the flip flops do not so your little one might not be able to wear them together. If I had ordered the 7, the sandals would have been way too big. Even witht the 6, they are slightly big on her. Otherwise, it's a cute outfit. I am just not sure how well it will fit after one round in the dryer. I will probably air dry it to prevent any shrinking.
I bought a size 5 for my four year old daughter and she is slim it fits beautiful and the sandles match perfect. the size is accurate. My daughter loves when I put it on her and I get a lot of complements. A must have.