My opinion
You know, you are the cousin who knows ASL and they know you know this. I think the more you concentrate on how this bothers you the more upset you get. Listen to your husband,, let it go, your heart is in the right place but there is nothing you can do about it, you already tried.
One day, if your cousin wakes up and realizes that her son will benefit with learning ASL, they will maybe come to you or maybe not, but for now, go on with yr life and it will help you a lot if you drop this....and just hope for the best for your cousins and let it go. You have a happy life ahead of you!
