A good sturdy machine is important but home machines are designed to handle 2-6 layers of fabric, even denim but have trouble with 8 layers like the crotch seam on pants. They may want to look at industrial machines which even on CL can run into real money but are durable. A solid home machine should handle a blanket but the absolute must have is a good well oiled Walking Foot. A walking foot makes all the difference in sewing layers such as quilts.