Consisting of Sabriel, Lirael, and Abhorsen by Garth Nix.
The Abhorsen are a family of necromancers dedicated to putting the dead to rest. The first book, Sabriel, feels almost like a separate story from the other two, which are tightly joined. Sabriel as a character struck me as cold and perhaps a bit proud, and for some reason I didn't like her book that much. There were a lot of vague hints about things that I took to be much more than they were in the second and third books.
I was starting to be concerned that the second book was all about "teen angst", with Lirael complaining, when things started to happen. She immediately became a (more) sympathetic character when her memory was tampered with by the leaders of the Clayr, her own people, something which I can't stand in any book. She is very quiet and perhaps shy because she doesn't fit in, but also somewhat headstrong and hasty, like Sabriel. As she meets up with Prince Sameth (Sabriel's son) and finds other companions, she begins to find her place in the world, a process that continues in the third book.
I suppose these books were interesting, but they somehow lack charm and appeal, for me. Perhaps it's because they deal so much with death. I'd like to recommend them, but I can't.