Marie Marguerite de Valois (1436–1473) was the natural daughter of King Charles VII of France

Charles VII of France

Charles VII , called the Victorious or the Well-Served , was King of France from 1422 to his death, though he was initially opposed by Henry VI of England, whose Regent, the Duke of Bedford, ruled much of France including the capital, Paris...

 and his mistress

Mistress (lover)

A mistress is a long-term female lover and companion who is not married to her partner; the term is used especially when her partner is married. The relationship generally is stable and at least semi-permanent; however, the couple does not live together openly. Also the relationship is usually,...

 Agnès Sorel

Agnès Sorel

Agnès Sorel , known by the sobriquet Dame de beauté, was a favourite mistress of King Charles VII of France, for whom she bore three daughters....

.

She had two sisters, Charlotte de Valois (1434–1477) and Jeanne de Valois (born 1439).

Marie married Olivier de Coétivy, Count of Taillebourg. Her older sister Charlotte married Jacques de Brézé, Count of Maulevrier, and mothered Louis de Brézé, seigneur d'Anet

Louis de Brézé, seigneur d'Anet

Louis de Brézé, seigneur d'Anet and comte de Maulevrier was a French nobleman, the grandson of King Charles VII of France by his natural daughter with his mistress Agnès Sorel.- Birthright, marriage, political intrigues :...

, husband of Diane de Poitiers

Diane de Poitiers

Diane de Poitiers was a French noblewoman and a prominent courtier at the courts of kings Francis I and his son, Henry II of France. She became notorious as the latter's favourite mistress...

. Allegedly Charlotte was killed by her husband for having committed adultery. Jeanne married Antoine de Bueil, Count of Sancerre.