Maybe it's the main character's own father who plays an important role in their family's Christmas celebration. He could be the one creating a warm and loving atmosphere.
It could be Santa Claus, as he brings gifts and is often seen as a magical and giving figure during Christmas.
It might be a character who shows kindness and generosity to others during Christmas, taking on a fatherly role in spreading joy and cheer. This could be a neighbor or a community member.