I found this simple Nativity cantata some years ago. It is in the public domain (meaning you may freely use it). It is largely based on simple arrangements of traditional carols. Though I am sure it was intended for church use, I think it would be great as a program at a family Christmas party, given you have a musical family. Childe Jesus (PDF) Contents:

1. The Promise (O Come, O Come, Emmanuel)
2. The Annunciation (Solos and Duet)
3. The Apparition to the Shepherds (The First Noel)
4. The Adoration of the Shepherds (Swedish Carol)
5. The Star (Tune of “Infant Holy, Infant Lowly")
6. The Wise Men (We Three Kings)
7. At the Manger (Tune from “Bring a Torch")
8. Mary’s Lullaby (Tyrolean Carol)
9. Song of Devotion (French Carol)
10. The Child Jesus (Danish Carol
11. Adeste Fidelis (O Come, Let Us Adore Him)