This Pinafore was handmade by me for a pattern test for the Alice Pinafore Dress by @iwillcrochet. It is 100% cotton. 

Flat Lay Measurements:
Waist: 13.25in, but it is adjustable up to 15.5in
Length: 25in
Shoulders: 10in (6in in between shoulder straps)

Model is 5'10" and has a 26in waist for reference. The waist is too big for the model.