I think everyone should think twice, three times, four or more times about having children.

That said however, she should have kept that particular opinion to herself. Whether you have children or not is between you and your DH. As long as you know about the history and are prepared to handle an autistic child should you have one, I don't see any reason why you shouldn't.

I might be concerned for someone whose family carried something like tay-sachs disease (a painful and 100% fatal neurological disorder), but even then I would never EVER presume to tell them they should reconsider reproduction.

I could not see it as abusive or neglectful for someone to have a child if they had a history of autism in their family.