Secrets in the Attic

Anna has always believed she had a typical childhood, growing up as an only child in a quiet suburban home. After her parents pass away, she decides to renovate the family house and start fresh. While clearing out the dusty attic, she discovers an ornate box tucked away in the corner. Inside, she finds an old, tattered diary dated just 20 years ago-long after she was born. As she begins reading, Anna is stunned to find that the diary belongs to a girl named Sarah, who seems to have lived in the very attic she's now clearing out.
The entries reveal a lonely, frightened girl who was kept hidden from the world by Anna's parents. But why? And who was Sarah?