My daughter about had a stroke when I allowed my grandaughter who was about 9 to sew on my new Bernina. I had an old Singer but it was tempermental and wanted her to have a good experience. I supervised closely at first and then when she had a good feel for the machine and how to use it safely, turned her loose. She was very creative and was so proud when she'd come upstairs with a bag she'd designed in hand or some other project. Also gave her free rein on a box of scraps an inexpensive material. She sews now and I eventually gave her my old Bernina when I got a new one. I agree that you should let them sew when they are interested.