Speaking of French carols and children, the song "The Friendly Beasts" is an English-language version of a very old French carol (going back to the 12 C. AD, by some accounts). The story, of all the animals being able to speak at midnight on the first Christmas and telling of their gifts to the Christ Child, seems well suited for kids. I'm wondering if any children's choirs have recorded it.

So far, I haven't been able to get my hands on the French lyrics.