Perhaps one might call this book an anti-holiday story, not because the book encourages hatred of the holidays, but because most Christmas stories are about the cheer and merriness of the holiday season, but Kim has never held Christmas in high esteem. That's especially true this time, because as she mourns her mother's suicide (who killed herself on Christmas day many years earlier), she also has to face the likelihood of her father's death.
One detail that merits mentioning is that the VA needs to be reformed, because the people who serve the country often receive terrible treatment from the agency, and Kim is downright frightened by the idea of the VA leading her father's battle against cancer. She has no faith in the agency, which is not uncommon. This doesn't need any further interpretation, actually, because it is a completely literal problem, but if one wanted to interpret it symbolically, perhaps it can be viewed as a complicated, unfortunate part of her father's willing sacrifice (which his service in the army was too).
Meanwhile, the story also outlines the basic shape of Kim's journey toward becoming a writer. She knows that these journeys are part of what it means for her to be an artist, but sharing her writing with others helps her to recontextualize her art as a social thing, a gift to others. Zeke is part of this journey as he comes alongside her in her life, but he doesn't understand. This can be seen as a symbol for subjectivity, because they want to know each other, but they can't really get close without struggling to teach the other about themselves. The relationship, like her writing, is art.
