The best way to find out would be to ask your local HH or other charities.
While they all work are for the same ends, the way they get there in different manners.
Thus, what may be welcomed in one area, may not be in others.
Start by asking and offering offer what you can ... that is ...
Are you willing to make the potholders? or just donating the batting?
or perhaps make something else?
Meanwhile you mentioned your friend's devotion to charity quilting ...
why not start with the group(s) that she worked with?
She already has an established connection for you ... follow it!