How nice of you to consider others, with your fabric blessings.
There are so many in need, where it will be appreciated.
Though I want you to consider first, if charity starts at home, in this case? Perhaps consider making quilts for your brother and any children/grand they have? Also her parents, siblings or close friends. Maybe memory quilts with photos included?
It could be a very touching gesture to give them quilts made from her stash.