Our across the street neighbor is the only person that I know besides myself that will rip up a garment for quilt fabric. You are lucky to inherit all those garments to turn into quilts.
I was taught at an early age to use every scrap of fabric for some purpose. My mother's 7 sisters handed down the dresses they could or would no longer wear to me. If I didn't like them or they didn't fit, they would be worked over until Mother or I one could wear them. I remember my mother working over one of her sister's coats for me. It was black wool with a black fur collar, not the most appropriate style or color for a 9 year old country girl, but I wore it. I was glad when I had a growth spurt and outgrew that black coat. My parents somehow managed to get the money to buy me a pretty pink coat, which I loved.