My youngest is Down Syndrome. My wife and I also started late as parents. I'm concerned about what happens after we are gone. All it takes now to off someone with a lesser "quality of life" is somebody with "custody" and a death-loving judge in his pocket. This terrifying possibility now has a precedent.
Anyway, bless your heart. Two with autism has to be difficult -- rewarding but difficult. My wife and I believe that God chooses people He believes to be strong to care for these different but special people. I've also mentioned to my wife that, perhaps, it's the ones who consider themselves to be "normal" who are the ones with the handicap.
All I can hope for is that I will be around for quite awhile yet as I started may family young and I have other children as well.....one of the things I teach them every day is that family means you take care of each other no matter what.....