The Lightkeeper's Daughter by Colleen Coble

Addie Sullivan grew up in northern California in a lighthouse.  It was a quiet and uneventful life until a stranger shows up and tells her she is not who she thinks she is.  Addie's world and identity is turned upside down as she is introduced to her "real" family.. the Eaton's.  Well known in high-society, the Eaton's are wealthy and powerful and like no family Addie has ever seen or imagined.  How on earth will she begin to fit it?  And as she begins to try, tragedy strikes. It seems someone is not happy to have Julia Eaton back from her watery grave and is determined to end the happy reunion.

An intriguing and exciting tale that draws the reader in and takes him/her on a roller coaster ride with emotional highs and gut wrenching drops.

This is book 1 in the Mercy Falls series by Coble. I am picking up book 2 at my local library today!