My granddaughter made her first quilt this past summer but I cut the pieces. She thinks she is ready for a rotary cutter so, toward the end of the process, I put in an old blade and let her cut measured squares from paper. Since the paper isn't as likely to slip, it's a way for her to get used to the feel of the tool. We talked about how to keep fingers out of the way but even so, I think we'll wait until next summer (age 11) before I let her do any serious cutting. It depends to some extent on the child and how well they follow instructions.