The Memory Book — Penelope J. Stokes

Phoebe Lange has it all--a Master's Degree, an adoring fiancé, and a future with unlimited possibilities--but something is missing. Orphaned at age five and raised by her grandmother, Phoebe longs for a past and a sense of connectedness, but it is not until she stumbles upon a scrapbook dating back to the 1920's that she discovers a terrible secret about her family's history which triggers an identity crisis. Phoebe becomes obsessed with the mysterious ancestor, also named Phoebe Lange, whom she is convinced is the key to answering the questions that have plagued her. But the answers may not be what she has in mind.