I made matching aprons for my daughters and their dolls. It's posted on my blog
here. McCall's also has a new pattern that has several styles of doll aprons - M6451. Jo Ann Fabrics sells this
kit for making matching aprons online. You can also buy a
kit from American Girl, but it only includes iron ons for the girl size apron (it's not included in the kit). Hope something here will be helpful.