First let me say I am sad to hear of your lose. And you have been giving a wonderful way to make memories, haven't you?
Wouldn't it be a good idea to check through the fabrics - keepers, donations and trash piles? I was given my friend's, Mary, fabric etc...many etcs lolo, to see to after she passed away. It can seem overwhelming. But easy when you realize many groups could use the items.
Are there charity resale shops in your area? If so, buy some large zip-loc bags and group fabric in them. You can use the bags also to put threads, pins (make sure they are in a small box) etc. To just give unsorted and unbagged things like this to the thrift/resale place makes them less likely to want it...and makes much more work for those working there too. Besides, they might not know good from bad etc.
Bagged and/or boxed sewing, emroidery etc items go well at yard sales held for charity. Call a few local churches etc.
My husband and I volunteer at an all volunteer food pantry (The Committee Food Connection of Blount County). I have started to go thru items folks always sem to give over to me, sort them, bag it and put out for the 'clients' at the pantry to take Free. If you have to come into get food, you surely wouldn't have money for quilting stuff --- works wondres. I have seen ladies with tears in their eyes. They are so happy to get it all.
Just a few ideas I hope can help you.
Julie