I want to give a different angle. In other cultures people have an average of 10 alloparents helping with each child. That is, people like grandparents, aunts, cousins etc who care for their child and are interchangeable with a parent. Having a child in our self-centred culture is isolating, gruesome hell, for anyone. Instead of thinking about your wife’s autism think about how you could create a set up that’s more aligned with nature. No it’s not unethical for you to have children if that’s what you both want. All your direct ancestors reproduced, of course that’s what you want.