Being a former Home Ec teacher, I always found that it was important to learn to do some hand stitching before you worry about the sewing machine. You didn't say how old the child was but they are never to young to learn to put in a hem, sew on a button etc. Aprons are a fine thing to start with but why 5? Children get bored really quick and 5 of anything is alot. If you are going to teach foods, you need to take a field trip to your supermarket and start with what is in the store and comparing prices etc. Home Ec is really an involved subject but at least you will be giving her a head start on what most young people get.
Basic sewing machine skills are great, threading, sewing a straight line and learning to layout a pattern. Also choosing the material for the project. Sounds like a neat field trip to Joann's to see threads and materials.
Hope this didn't get too involved but I really feel that the basics are important.