There are so many ways that you can help her. If I may offer some suggestions to you....
A T-shirt quilt is nice but may be too difficult to do at first. So, maybe suggest that she collect the t-shirts and set aside to figure out how many and which ones to make in the future.
Think about shirts and jeans. A rag quilt with jeans/slacks on one side and shirts on the other. Don't forget to save the pockets for a little extra.
Now, this may be going too far, so please excuse.... Make some blocks out of his regular clothes, enough for a small pillow sham. You could suggest socks or misc items to use as 'filling' for the pillow.
A miniature quilt that she can have with her at all times.
There are alot of posts on making these here. So sorry to hear of your friend's loss.