I would almost say maybe she didn't understand the blood, sweat, tears, and thought and above all love that goes into a quilt. But if she is a quilter and that is where you and your sister got your start, I just don't know what to say.
I imagine her age could play a big part in her reasoning. If I lived in IL, and went to a Goodwill and found it, and then read something like this, You can rest assured I would return it to you and your sister.
I suppose you can know whoever has the quilt will definately enjoy and admire it.