My DGD is now 10 y.o. When she was 9, she made a wall hanging for the dining room in her house. Her mom is soooo proud of it! Her mom (my DD) does not have time to sew although she knows how. She is a physical therapist and works hard in addition to my DGD and her twin brother being in all kinds of activities, and her husband too.
Now my DGE is working on a pinwheel quilt. I showed her how to cut the pieces and match points etc etc. She is doing the whole thing herself in lightweight flannel - a Christmas pattern to the materials. She has definite ideas on the arrangement of the colors etc. I AM SO PROUD!
As someone else noted, this is a wonderful bonding tool. We were close before but are even closer now.
She sews on my featherweight and does a wonderful job of keeping straight and the 1/4 inch seam.
KEEP THEM SEWING! no matter what the age. It can be supervised and arranged to fit the time frame in their little lives.