Oh dear Laura,
What an ingenious idea. As a retired teacher, I understand the need to add a new dimension to a child's experience. Before I retired I was director and teacher for a group of pregnant and parenting teens in an alternative school. One of the skills I thought all girls and boys should have was learning how to sew. They all enjoyed it so much and we ended up with some really talented students who I am sure will one day persue sewing as they become situated and stable. I have started collecting vintage and newer machines at thrift stores for $15.00 and under, refurbishing them, and giving them to the students who continue to be interested. Bless you for your initiative in bringing something new and useful into those preschoolers' lives. My mother never sewed, but I learned in 8th grade home ec. My mom gave me my first machine in 1959, a Singer Centennial Featherweight. The first thing I made was slipcovers and curtains. I was 18 years old. I still have it and it works as well as it did back then.