Wife and I afraid to have another kid because of how many cases of autism and other mental disorders run in her family

I'm not shitting on autism. I would not love my child less if they were to be born with autism on any part of the spectrum.My wife comes from a large family. several siblings from a parent who also has several siblings who each of several kids. Almost every single one of my wife's generation of kids has at least one child with autism ranging from non-vocal to mild aspergers. Recent developments in our own daughter's behavior have also convinced us to sit down with her school and at least rule it out, but she's already 8 so I doubt that's what it is.The fact that, especially among my sibling-in-laws, every parent has one child with autism really scares us. We love our daughter and we aren't 100% sure we want to have more than just her (even without this topic). If it turns out she's on the spectrum as well, we won't and we'll just focus on her. If she's not, we got lucky with the statistics in the family and I don't want to risk it.As selfish as this sounds, we have spent our entire 20's working and going to school and raising her without doing really anything for ourselves. We are finally seeing the light at the end of the tunnel and about to be able to afford to give our daughter everything she deserves, we're about to be able to enjoy our lives with a significantly less amount of stress after almost 10 years of one car repair away from being on the streets. I don't want to risk that just to have another kid.My wife was hanging out with her sisters when they asked about our plans. She made the mistake of mentioning how she was scared how often autism pops up in the family and how lucky we all were that the cases in the immediate family were manageable and even at its worse all our nieces and nephews will be able to lead functional lives. It's not the case for their cousins. One of her sisters was so deeply offended by this. As if she felt it was only right that we have another kid since everyone else has more than 1, and everyone else is dealing with autism of some form so why can't we?I just don't know how to take any of this. Yes my daughter wants a sibling, yes we would like a child between ourselves (my daughter has been my step-daughter since she was a year). But we don't want to take the risk of having a child who will need our full attention for the rest of our lives. I understand that parents everywhere do this, I understand that no one wants their child to be born disadvantaged, and of course if it happened I would step up. But as it stands that is not our reality and we have a choice to not risk making it our reality.TL;DR: Every adult in wifes very, very large family has one child with autism. Our daughter doesn't and we selfishly don't want to risk it for ourselves no matter how much we want at least one more kid. via /r/Parenting http://ift.tt/2hl2oTS