Whether schizophrenia is “nature or nurture” has not been resolved. It is believed that schizophrenia has a genetic component, but no one knows this for sure.
Having a family history of schizophrenia increases the likelihood of future offspring developing the disease but the risk is very slight. Whether or not someone develops schizophrenia, depends on many factors.
I would be less concerned about your future children developing schizophrenia than I would be about how her untreated symptoms might impact your relationship. You did not mention how much interaction you have with his mother and he with her. Problems with in-laws can be distressing for a new marriage. In fact, it’s a relatively common reason for divorce. You’ll have to decide whether or not you want to marry given his mother’s problems. Consider how her problems might impact your marriage.
I hope this answers your question. If you would like to write back with additional details, I may be able to provide you with a more specific answer. Please take care.
Dr. Kristina Randle