"Every child should understand the true force of the will. He should be led to see how great is the responsibility involved in this gift. The will is the governing power in the nature of man, the power of decision, or choice. Every human being possessed of reason has power to choose the right. In every experience of life, God's word to us is, “Choose you this day whom ye will serve.” Joshua 24:15 . Everyone may place his will on the side of the will of God, may choose to obey Him, and by thus linking himself with divine agencies, he may stand where nothing can force him to do evil. In every youth, every child, lies the power, by the help of God, to form a character of integrity and to live a life of usefulness. Ed 289.1"
"And if it seem evil unto you to serve the Lord, choose you this day whom ye will serve; whether the gods which your fathers served that were on the other side of the flood, or the gods of the Amorites, in whose land ye dwell: but as for me and my house, we will serve the Lord."
Ellen White directly references Joshua 24:15 in this passage.
"The parent or teacher who by such instruction trains the child to self-control will be the most useful and permanently successful. To the superficial observer his work may not appear to the best advantage; it may not be valued so highly as that of the one who holds the mind and will of the child under absolute authority; but after years will show the result of the better method of training. Ed 289.2"
"Train up a child in the way he should go: and when he is old, he will not depart from it."
The proverb directly addresses training a child, and EGW's passage discusses the importance of training a child to self-control, which aligns with the principle of proper upbringing. The confidence is increased slightly.