Some suggestions for what to share with your kids:
The Branch is a term used in Zechariah for Jesus.
Zechariah prophesies about the rebuilding of the Temple. Jesus prophesied about it too, but he was speaking of his body.
From The Lutheran Study Bible on Romans 16.25-27: Paul’s closing words encompass the entire good news of God, from the prophetic OT writings to the proclamation of Jesus Christ being made known to all nations. God’s eternal being, His wisdom, knowledge, and power, are all far beyond ours. He calls those of faith to respond in obedience to His will. The Gospel of Jesus Christ was entrusted to Paul and faithfully proclaimed among the nations in accordance with God’s will.