In the Greenwood He Was Slain

When Jennet witnesses a man abandon four collie puppies on a country lane, she resolves to rescue them from certain death and bring the perpetrator of this outrage to justice.
Her search leads her to a long-abandoned playhouse in the woods of an abandoned construction site. On another day, the purchase of a Valentine-themed music box and a dozen books in a series draw her into a story of Evanora, a young girl who experienced love, betrayal, and murder in this very house.
Why does Jennet feel an affinity for Evanora and her house and what does it portend for her future?
The old diary, mistakenly added to a box of old time series books, contained the reflections of a young girl with whom Jennet finds a disturbing commonality.
What part will the long-abandoned Valentine House in the woods play in Jennet's struggle to capture a person whose business deals with dumping unwanted pets?