Remember that spiritual interest is a function of God’s grace. Ultimately, we can’t manufacture it in our kids.
Beware of the dangers of making your kids have a quiet time or of providing incentives for it.
One of the best ways to encourage them to spend time with the Lord is to model it. (1 Cor 11:1; Phil 3:17, 4:9)
Be sure to present the quiet time as an avenue for a relationship to be enjoyed, not a task to be done.