Additionally she held the position of a lady-in-waiting to his sister-in-law Elizabeth Charlotte, Madame Palatine, the Duchess of Orléans.

The Duchess of Orleans wrote "[she is] a stupid little creature, but she [has] a very good heart"[5] but described her as "lovely as an angel, from head to foot".

[6] Louis XIV displayed renewed enthusiasm and adorned himself with diamonds, ribbons, and feathers,[1][3] reportedly influenced by his affection for Marie.

The king found this rustic style delightful, and the next day many courtiers adopted the new "fontange" hairstyle,[3] except the Marquise de Montespan, who thought it was in "bad taste".

Two pet bears belonging to Montespan escaped from their menagerie and managed to find, and destroy, Marie's apartment in Versailles.

In April, Louis granted her the title Duchess of Fontanges and a pension of 80,000 livres,[3] as was his usual habit on ending love affairs.

In 1681, Marie suffered a high fever and was sent to the Abbey of Port-Royal, where, according to some sources, she gave birth prematurely to a stillborn girl in March.

Marguerite Monvoisin, the daughter of sorceress La Voisin was the first to accuse accomplices of her late mother of poisoning the duchess.

Although rumours of poisoning abounded, dubious evidence from various unreliable witnesses who either recanted or contradicted each other meant no charges were ever laid.

[citation needed] An alternative suggestion is that she was killed by a rare form of cancer, which occasionally develops after a cyst on the placenta is expelled during pregnancy.