How to Discern Between Fruitful Suffering and Destructive Suffering

How do you determine what's fruitful suffering versus destructive suffering longer version? We recently took in two foster children One of them has much deeper problems than we were told about our four biological children are having a very hard time living with this child. I mean, is there a threat of physical harm and physical violence? Is it just a some difficulty in adapting? Has there been past sexual abuse or you worried that that could be perpetuated on your children?