Secrets - Jude Deveraux

At age twelve, Cassandra Madden fell in love with Jefferson Ames, a young man she met at one of her mother's business conferences.
To cope with the pain of a cold mother, she always held on to this unrequited love.
Years later her heart still yearns for Jeff, and she travels to Williamsburg, Virginia, where Jeff, now widowed, lives with his daughter.
Cassandra becomes the child's nanny, but he's yet to even notice her.
Then one day she hears shots coming from the mansion of Althea Fairmont, an eccentric woman and great actress.
Cassie runs to investigate and suddenly her life is turned upside down.
She learns that everyone has secrets - and Cassie must unravel those secrets, if she and Jeff are to find happiness again.