The only way a child can be disobedient is if he knows he is being disobedient. A child has "invincible ignorance" as they have not yet come of age to discern what is right and what is wrong--in God's eyes.
The only way that you or I or anyone would make it into heaven is through God's mercy. None of us is truly righteous. We all have sinned and fallen short of the glory of God. And we are all imperfect. We need to trust that God will have mercy on us--as sinners and trust in His grace.
The wrath of God is for those who are truly unrepentant. The disobedient. Those whose pride is so great that they don't feel they need God in their lives. Those who don't seek the will of God but rather do their own will.
For them, we can only hope that God's mercy will reach out to them as well.