You're right, that is just plain rude, and insensitive, and selfish on the DIL's part. I feel bad for those boys, too. Sometimes adults have no idea how much they hurt a child's feelings when they are so thoughtless.

Years ago I taught a childrens class in macrame, and had one boy who really stuggled. He was very hyper, and I practically had to stand over him to keep him on task in tying every knot to complete a plant hanger for a pot he had made. It took him a couple weeks, but he finally got it done. When the parents came that day, this kid's dad said right in front of everyone that he didn't believe his son made it, that he knew his son couldn't make anything that nice. You could see his son was crushed. I felt so bady for him.