Sabriel will primarily be giving gifts to her students and CR, since even though her world probably doesn't have Christmas (though they likely do have some sort of solstice celebration), she likes the idea of it.

Her students will each get a dagger that Sabriel put some basic spells on. (Like staying sharp without maintenance for longer than they should and causing at least some damage to undead and ghosts, even if they don't have physical forms.) and a set of notes detailing a few minor and useful spells. (For example, one that will keep a character warm in cold weather and prevent frostbite, but is exhausting to maintain for more than a few hours.)

Also, she might attend a party or two. Or maybe just invite a few people over to share some mulled wine.