Fivepaws, check out Sharon Schamber's method for squaring up blocks - she takes a block that is 1/2" out of square on one side and makes it perfectly square - without any cutting! She's using an applique block in her demo. This would preserver your mom's handwork :)
http://sharonschambernetwork.com/Cla...h-A-Block.aspx
<no affiliation, just a fan>