Becky Brock has a nice arrangement of the Pastorale from Handel’s Messiah in her book of solo Christmas music, and Dewey Owens has a couple of pieces that would be appropriate for this, like the Pastorale from the Corelli Christmas Concerto, in his Wedding Music for the Advanced Lever Harpist. Since it’s advent, O Come, O Come Emmanuel would be appropriate. Largo from Winter by Vivaldi (several people, including me, have arranged that one).
Jesus, Joy of Man’s Desiring is a classical piece by Bach that is heard at Christmas frequently. Sylvia Woods has a nice arrangement for lever harp.
Thanks to A Charley Brown Christmas, Fur Elise has become associated with Christmas as well, and Barbara has a nice arrangement playable on Lever harp in her book Classics on Request Vol 1.
Also Gounod’s Ave Maria is a nice choice. And it happens that it is in Barbara’s Classics on Request Vol 3.
Darhon Rees- Rohrbacher’s two Christmas books are wonderful. As I recall, there are some pieces in each book that are printed separately, one arrangement for pedal, then the same arrangement for lever.