A: I think the strap would definitely fit. However, I'm a tall person who wears xl, and the back support felt off centered to me when I tightened the strap. If that doesn't bother you the shelf type pillow is really awesome.

A: P.s. I use it unbuckled on my lap too and still works well. Just remember to always bring baby to the breast and not breast to baby and you will save your back.