Heb 11:24-26, 24 By faith Moses, when he became of age, refused to be called the son of Pharaoh’s daughter, 25 choosing rather to suffer affliction with the people of God than to enjoy the passing pleasures of sin, 26 esteeming the reproach of Christ greater riches than the treasures in Egypt; for he looked to the reward.
The next faith would be Moses’ personal faith in God. His actual age when he placed his trust in God is not mentioned because it is not important but age of or level of awareness, maturity and accountability is. Moses by faith starting from seeing his parents’ faith to embracing what he was taught saw God who is invisible, and drew to God with a mighty faith that reckoned on Him as being more real than Pharaoh. The parents that entrusted him to God when he was born entrusted him to God as he grew up for his salvation.
Every child at the age of understanding, accountability must be taught and encouraged to have faith in God. They themselves must be saved and not live on the faith of the parents. Each parent as their duty must talk to their children about Jesus (gospel) and then spend time telling Jesus about their children (prayers).