Jox - that is shameful. How dare she? Ugh. She sounds quite awful as a person and grandparent, talking about having her grandchildren terminated. (My brother has autism, and while as a child he obviously had a lot of problems, as an adult he's pretty high-functioning. And even if he wasn't, a diagnosis is not the end of the bloody world!)
Re: down's syndrome - that's a different story as it likely comes with many developmental, psychological and physical challenges for the child which could range from mild to severe and affect quality of life. It is an extremely personal and difficult decision whether or not to terminate and I'm not going to judge one way or the other, and I've had family with Down's that I loved dearly.