The Secret of Magnolia Manor — Helen Wells

Flight stewardess Vicki Barr has a new route from New Orleans to Guatemala City. Her mothers friend found her a place to stay in between runs in the French Quarter of New Orleans. It is an old family house owned by Paul Breaux. The other residents are his orphan niece, Marie, whom he treats like a servant, Madam de Fes, an elderly paying guest who is also a distant cousin, and Sarah, the cook. Vicki gets all involved in the families history in order to find a will that would appoint all the family belongs and money to Marie instead of Paul.