Shadow Witch: Book Four of the Wizard Born Series

Two months without a major crisis has lulled Jamie and his friends into a false sense of security. On graduation weekend, their lives are thrown into chaos once again when a seven-year-old runaway girl shows up on Fred's doorstep, desperately needing their help.
Sammi Price is a Shadow Witch, with a rare power that has enabled her to find the people who are best able to protect her from her abusive foster father, Duane Gundy. He's violent, obsessive, and fiercely determined to track Sammi down and bring her back at all costs, and Jamie, his friends, and their families must pull together like never before to stop this relentless madman.