First, no adult ISIS should expect to be free in the next 10 years. I suggest standing up prompt military tribunals in NES (Syria) under current govt. authority and begin the prompt summary judgment of ISIS fighters.
A. Membership in ISIS
B. Commission of one murder or rape
C. That they are not Syrian.
Once that has been determined prisoner may be executed as unlawful combatants under Geneva.
A. Those who confess: 10 years at hard labor. Those who stay in Syria should be tasked with dealing with the bodies of their victims.
B. Those who don't confess: Trials held where the punishment is up to life at hard labor.
Most likely the parental rights must be terminated and the children placed in families, either in the counties of parents' origin or with volunteers in NES who will receive a stipend for raising the child. They must be deprogrammed and get counselling.