For starters, if they fail, they get placed with a foster family and registered in to public school, during their teen years.
Worst case scenario is that the kids are placed in fotercare with a couple who make their living warehousing kids for the state. They are abused and raped in fostercare , maybe get AIDS, maybe get pregnant, who knows. After a couple of years of fighting the system and jumping through DSS's hoops, the now bankrupt couple ( legal fees are expensive) is TPR'd because they refuse to comply with some egregious demand of CSS, like "Get a divorce" or something equally violent. The kids are now freed for adoption by complete strangers, and the state will realize the adoption bounty made law by Adoption 2000 ( Clinton's doing.) Your children grow up to hate you, to refuse to have anything to do with you, because they have been brainwashed to accept the state's version of events. Worst case scenario: Your children , who you love more than life itself, grow up to be complete strangers, and also grow up to be individuals profoundly damaged by the experiecne of being taken from their parents and homes , placed in fostercare and the adopted to complete aliens. Bad enough for you? Happens every day