The other day in the school library I spent half an hour pulling books about winter celebrations. With about 40 books assembled in total, it was interesting to compare the size of the stacks for Christmas, Hanukkah, Kwanzaa, Diwali, and Ramadan (yes, I know Ramadan isn't a winter holiday; I was just following orders). Christmas had the most books, but only by a hair over Hanukkah. Kwanzaa was probably the most over-represented in terms of books per observance; there were four Kwanzaa books, tied with Diwali and one ahead of Ramadan. More telling than the numbers alone, though, was the way the different holidays are presented both in the books themselves and in the layout of the library.
The Ramadan books and three of the Diwali ones are nonfiction titles. The way they all present their subject is totally othering: they're absolutely respectful and even enthusiastic about the holidays, but they're written for a blank-slate audience and so have something of a "look at this crazy thing!" tone about them. And they're shelved in the "Religion" section of the Dewey Decimal classification (the 300s), along with the Greek myths and ancient Egyptian gods. You can also find a few Hanukkah titles in that section, but tellingly nothing about any Christian holidays.
In addition to the "Rookie Read-About Holidays" Hanukkah books, there are lots more titles in the picture book section. A few of them are basic "my first Hanukkah" texts, but lots more of them are real stories written to celebrate Jewish culture. There are more Hanukkah picture books by Eric Kimmel alone than there are books about Diwali and Ramadan combined, and lots of other authors are represented as well. There are also two Kwanzaa picture book stories in the same vein; one more explain-y one and one actual story.
In most of the Christmas books, on the other hand, Christmas is pretty much just a background. With so many of the cultural features of the holiday part of the reader's assumed knowledge, authors write stories where characters have interesting experiences and learn valuable lessons at Christmas time, but rarely engage with the holiday in any real way. To go by nearly all of the library titles, Christmas is about exchanging presents and finding ways to be happy with your existence.
Of course, part of the reason for that is the public schools' careful avoidance of any appearance of Christian proselytizing. The Hanukkah and Kwanzaa books get spine labels with the name of the holiday and culturally-relevant pictures; Christmas books' tags say "Holiday". The library will stock books explaining the origins of Diwali in Rama and Sita's return from exile, but you won't find a single mention of Jesus (except maybe from Tommie de Paola). It's meant to be sensitive, but causes it's own problem: it positions Christianity as the unspoken default and marks all other faiths as other.
To an extent, that's fair; there are more nominal Christians in that particular school than followers of any other single religion. But if you ask me, all religions are interesting, including Christianity! I wish we could trust schools and teachers—and libraries—to disseminate information about different faiths in a fair, even-handed manner. But we can't; we can't even manage to talk about science that way. So this is the situation we have. Not a huge problem, just... not quite right.