I Thank a Fool (1962)

After mercifully killing her terminally ill lover, Dr. Christine Allison loses her medical license and spends two years in prison. Once she has completed her sentence, the lawyer who prosecuted Christine, Stephen Dane, hires her to care for his emotionally unstable wife, Liane. Christine takes the job, but when Liane's allegedly dead father reappears, Christine sets out to reveal the family's dark secrets.