The Governess — H.R.F. Keating

When Harriet Unwin takes the position of governess in the well-to-do Thackerton household, it would seem that fortune has smiled on her at last. That is until William Thackerton is found stabbed and Harriet is accused of murder.... In a desperate attempt to prove her innocence, she embarks on a daring scheme to save herself from the gallows. In doing so she uncovers the dark secrets which the family is trying to hide behind a veneer of Victorian respectability.