I bet she wouldn't even notice if you sent 3/4 of what she gives you to a prayer shawl ministery like Prayers & Squares. You might even suggest she might really like to start such a ministry in your church. Do it some time when she isn't gifting. Keep the fabric you really like and pass the rest along. (I'm just starting a stash and do lots of charity stuff, but I have to buy my fabric most of the time.) A small fat quarter is enough to do a lot of fun stuff, without loading down your sewing room.
Have fun, Gwyn