ooooh. my, that is a beautiful heirloom, your great gran did beautiful work.
I imagine that you and your mum feel very blessed to have it.
It is a big responsibility to look after such a treasure. At our LQS we were chatting today about how scary it is to decide whether to try to carefully clean and/or mend an heirloom. We were privileged to be shown a yo yo quilt with hundreds of tiny 1 inch yo yos made in the mid or early 1800's and another blanket of silk and tulle pastel yo-yos of about 3 inch diameter. The tiny meticulous whipped stitches were wonderful to see.