Notes on fit: Everyone is different. What they can and can't tolerate is largely preferential. Some people can wear more than one size and that's OK. It's like going to the clothing store and being able to buy jeans in both a size 6 and a size 8. They both fit, maybe one's slightly looser.

Too Small: feels uncomfortably tight, digs into baby's legs, it's crazy hard to get baby in.

Too Big: baby feels insecure, your legs bump the baby as you walk, your back aches after a short time, sling slips off your shoulder