Her older sister Maria Teresa was her eldest surviving sibling followed by her brother the future Ercole III d'Este, Duke of Modena.

The eldest Maria Teresa Felicitas married her second cousin, the Duke of Penthièvre, the wealthiest man in France and the future in laws of Philippe Égalité.

Maria Fortunata also married a cousin, Louis François Joseph de Bourbon, the heir to the Prince of Conti.

Many at court said this state of affairs was due to the influence of her husband's mistress, Marie Anne Véronèse, known as Mademoiselle Coraline.

Her niece would eventually marry Louis Philippe Joseph d'Orléans, Duke of Chartres, the future Philipe Égalité, in April 1769.

In 1770, the marriage of the Dauphin of France, the future Louis XVI, and the Archduchess Maria Antonia of Austria took place.

Marie Fortunée, as she was known in France, and her husband were one of twelve couples invited to dine with the newlyweds in the Opéra of the Palace of Versailles, which had been constructed for the royal wedding.

During the crisis of 1789, when the Estates General was called at Versailles, Marie Fortunée supported the royal family and even took part in a march to the Church of Saint Louis.

The princess was the heiress of Marie Fortunée's elder brother, who had lost the duchies of Modena and Reggio in 1796 as a result of the Napoleonic creation of the Cispadane Republic.

1801 saw the reunion of Adélaïde d'Orléans and her mother, the now dowager Duchess of Orléans, in Barcelona after her release from prison and exile from France.

She moved to the convent on 19 October with three of her maids and her faithful friend, the comtesse des Roches, who had accompanied the princess all throughout her exile in Europe.