I agree on using a real machine! My mother put phone books under the pedal so I could reach it and taught me on her machine when I was 5..I started with very simple pillows, and such till I learned to control the machine. My first quilt was large squares sewn together...very simple and success related...I have been hooked on sewing since

To let my DGD learn to run my machine, I drew lines on paper and untreaded the machine and let her stitch on the paper following the lines. She learned to pivot on the corners and to go around curves before we got to fabric. Then I started her on a can coozie and a pillowcase. I drew lines on the fabric and she stitched them until she learned to follow the guide on the thrat plate for seam allowances. We made a small doll quilt too. Pillows for the bed are good practice and boxer shorts or pajama pants are too. There are lots of beginning projects for a young sewer to learn on.

my grandaughter has just turned 8 and I bought her a mini sized sewing machine she keeps it at her home and uses when she is sewing on her own, it has a good guard around the needle, when she is at mine she uses my machine with the foot pedal on a box and speed turned down low. I just let her decide what she would like to make, first thing was a slipper bag for a friend at school, then she wanted a pin cushion and she made a cushion for her mum for mothers day. Next project is a skirt for her little sister. I usually cut out for her and iron and she does the rest. She is left handed so have had problems finding suitable scissors. I find if I let her follow her own ideas she is really involved. I am sure your grandaughter will enjoy her time with you.