I am in a relationship with a man who's ex wife was diagnosed schizophrenic in her mid 30's.  They have a 10 year old daughter who now lives with him and I.  I have seen two different psycholgists to talk about my concerns and they both said that she has a 25% change of developing the disease.  They both said that it usually shows in mid to late teens to early twenties (her mother is not typical having developed symptoms in mid 30's).  There is no research showing symtoms earlier than mid to late teens. Their advise was to get her therapy early in order to monitor her behavior. 

Please research the subject as much as possible on your own to gain a better understanding.  There is so much information online as well as chat rooms where you can talk to others who are dealing with the same issues.  There is no research that has found any cause for the disease in any of the information that I have read or gained from doctors so it is possible that people simply introvert inside their own heads and somehow cause it within their own minds.  I have discussed this theory to both psychologists and they both said that it's possible. They explained it would be the same as if you constanty tell yourself negative things (i.e. I'm fat, I can't do that) then they become part of you. Just as when you constantly tell yourself positive things (i.e. I look great, I can do this) that also become part of you.  It does not mean that anyone brings this upon themselves.

They both said that schizophrenia is a very difficult disease because there is little chance that the patient will continue medication and treatment.  There is also the sad reality of the disease that limits the mind of the victim to a place where they cannot "reason".  I read on one website that their minds simply cannot access the proper file locations inside their memory much like a computer that crashes.  One reasuring thing that I've read in several places as well as being confirmed by the doctors is that the earlier pchizophrenia is detected and treated the better the results and success of the patient.  I truly hope your soon to be ex-husband is one of these lucky people.  It will also make a huge difference if he has a good support system that will push him along with his treatment. 

My point is, we cannot know what's going to happen or why.  Your daughter and my new daughter are both good girls who are doing just fine. All either of us can do is learn, hopefully make the best decisions we can, and enjoy the time we have with the people we care about.  And try not to project our fears (I know I'm guilty).  I try to think at least twice a day "it's going to okay, it's going to be okay".  And do you know no matter what else has happened to push that little negative thought "I can't handle this", that tiny positive thought gets me through. It's been working for a year now.  You can do it!