personally id never keep a dog that was a risk.
id have it put to sleep i would not re home as that may run the risk of the dog being moved on again to a home with children and in my veiw that wouldent be worth the risk.
however id also never leave child with a dog unattended ever.
our dogs are kenneled outside,and have time with the kids supervised only.
some dogs are a risk and there no reason why.
some because they are not trained /looked after properly.