There are studies and there are studies, so one must evaluate any study of human behavior with a grain of salt. A recent study by the University of Copenhagen concludes that children who have lesbian mothers are less likely to encounter serious mental illness in their lives. The researchers believe this emerges from dealing with issues in their lives at an earlier age and learning how to handle conflict. Their mothers have endured many serious issues throughout their lives as they seek to attain a stable marital relationship and raise children who may encounter prejudice at school and among playmates.
There is a certain logic in the reasons advanced why children grow up mentally stronger than those who have less serious mental strains in childhood. Of course, dealing with prejudice can also have the reverse result and lead to greater mental illness. We will, for the moment, accept the findings of this study.