I like this sign too. We should be always praying over our children. Pray for the friends they are around. Pray for a future spouse for them. Pray they will stay on fire for the Lord and their service to God too. Prayer of safety and protection. Pray that we as parents will set the the godly example we should set for our children. Pray they will remain pure until marriage and stay pure toward godly living.
The Most important one is to pray for their salvation so they will be saved.
Their salvation is the most important because that will determine their eternal destination.