What size for diney store infant costume?

[kitn]

HI!
My baby will be 9 months this halloween. She is a bit chunky but not really long. If I go with the disney store weight chart she would be 18 months. if I go with her length she is 12 months. Do these infant costumes run small? I also will be using the costume in November when we go to Disney. So I am wondering if I should get the 12m or the 18M. Also does anyone know if they sell them at the Disney store? So if I did get the wrong size I could quickly exchange it.

 

[MSSANDRA]

Go with the larger size. Sometimes they do run small and if it is cold you might need to layer something under it. Our dis store does have some costumes, more around halloween.