You should have this documented. Many states have a documentation team. Check with a local quilt guild to find out about it. They take pictures and get all the information they can about it. Who,what, where, when, and why. It becomes part of the state quilt history. They also like to have some information about the quilter. Write down as much as you know about your grandmother and keep it with the quilt.
Having the picture is also valuable in case the quilt (God forbid) it is stolen.
This is a beautiful quilt and a wonderful treasure.