So Far Away by Meg Mitchell Moore

Poor Natalie Gallagher is not having a good year. First, her best friend, Hannah, seems to have disappeared from her life. Her parents are getting divorced and her mom is not handling it well at all. Then she becomes a victim of cyberbullying.

As part of a school assignment, she starts working on a genealogy project and ends up at the archive library, where she crosses paths with the archivist, Kathleen, whose own teenage daughter is a runaway. Kathleen can see that all is not well in Natalie's life and tries to help her. The two, along with fellow archivist Neil, become engrossed in a journal that Natalie found at her house describing the life of an Irish maid named Bridget, who may have been related to Natalie. As the cyberbullying intensifies, Kathleen frantically tries to do anything she can to help this young girl.

This is a very engrossing story--I read the whole thing in one day. You really feel for Natalie, whose parents are so wrapped up in their own lives that they have no idea of what's going on with their daughter. And you love Kathleen, who is trying so hard to save someone else's daughter, after she couldn't save her own.