You're right; we aren't told exactly what the angels who appeared to the shepherds that first Christmas night looked like, but I honestly wouldn't worry about it. The Bible says their appearance was glorious beyond description, and that's all we really need to know (see Luke 2:8-14).
Hopefully, the children at your church will realize that angels aren't just like us, but are heavenly beings sent from God. I hope you'll also help them realize that the angels who appeared that first Christmas were sent to deliver the greatest message the world has ever known: God's only Son had come into the world. Their message still echoes across the centuries: "Today in the town of David a Savior has been born to you; he is the Messiah, the Lord" (Luke 2:11).
Christmas is still many weeks away, but already stores are filling up with decorations and special sales and signs urging us to get our shopping done early. Don't let this divert you from the true meaning of Christmas: God loves us so much that He sent His Son into the world to save us from our sins.
Make Christ the center of your Christmas this year -- beginning today. In the midst of our world's upheavals, find your peace in Him. He came to tear down the barrier between us and God, a barrier caused by sin. And now He offers us peace -- peace with God, peace with others, and peace in our hearts. May this be your experience, now and forever.