As a 4H sewing teacher, I say teach them to hand sew first. Neat hand sewing is very important when constructing garments. I have a very hard time getting the girls to do any hand sewing because they think everything can be done on the machine. My mother started me out about age 5 with embroidery. That's more fun than just hand sewing but you will use kinda the same stitches when sewing by hand. I still love hand sewing to this day, embroidery, quilting and the such. I also like the idea of sewing on paper without any thread. It makes the holes so you can sew where you've sewn but not the thread to get jammed. Just sew along the lines of notebook paper to encourage straight lines. There was just a thread not too long ago where she said she couldn't sew a straight line. Practice, Practice, Practice.
And a good machine helps.