Is it time to call a truce? Offer to help her make it. $150 worth of fabric is a shame to waste. If you help her make it she will definately realize what a job it is to create a large quilt. At least think about it.
Years ago I saw a picture of a Mariners Compass, a very complex one with around 150 pieces per block. I asked my mother if she'd make me one. She said, "You'd better shake your head and see if it rattles, I'm not making anything like that. If you want one you'll have to make it yourself." (didn't hurt my feelings at all--we both laughed) I now have a Mariner's Compass quilt that I made myself and I understand why mom wouldn't make it! I should mention that my mother made exquisite quilts completely by hand. And that she was totally blind in one eye, had poor vision in the other, suffered from Lupus, arthritis, Collegens disease and Raynods--I had no idea what I was asking of her at the time.