Infants seem happy as can be cinched up in a cloth wrapped around their mother's or sister's waist. I've watched her get situated a few times, but can't figure out how it all stays put so securely. Patience sort of bends over a bit and swings Isabella around onto her back side with legs splayed. With her other free hand, she whips a cloth around Isabella's bottom, around the other side and tucks everthing in on the front. No knots or velcro involved!
Isabella is still quite small, and not yet able to roll over. Sooner or later her feet will stick out the sides - right now obscured by her mother's elbow.