Having experienced the same thing with a wedding quilt I made for a friend of our daughter, I know the feelings you're going through. I picked the perfect pattern to have meaning for them and we all know how much time and thoughts of the person we put into these. About a year later they came to town with the quilt in tow and asked if I could repair it - the dog had eatien a humungeous hole right in the centre of it. I took it home and that gave me a cooling off period and after really looking at it, realized that I would never be able to repair it. The friend is a Geriatric Nurse and thinks everything should be bleached and yup, that's what it looked like she'd done or washed it in very hot water a gazillion times.
This made me sit and have a talk with myself. "Self" explained that I had enjoyed making it for them and all the planning and I enjoyed giving it to them for their wedding. Once a gift is given, it's the receiptient's and what they do with it is up to them.
I wouldn't repair it and I wouldn't harbour any ill feelings - they just didn't know any better and accidents happen. Just let it go.