Love covers a multitude of mishaps. The answer depends on the reaction of the initial damage. If it makes you and your son happy to repair it, do it. If there is going to be any resentment attached from either side, let it be.
We all fail each other many times and altho' you put so much of yourself into making something special for your son to enjoy and hold dear, at the end of the day it's a possession, not the definition of your relationship.
Yes, it does hurt tremendously to see your work destroyed, but as others have said so much better, when it is given away you no longer own it. It's the risk any quilter takes on when giving away a project. It made you feel good to make it. That's your true payoff. It's icing on the cake if the recipient loves it and uses it, no matter the outcome.
You're a wonderful, caring mother that brings much joy to your family. I hope you've gotten some relief after reading all the posts and listening to your heart. :thumbup: