Once widowed, Blanche retired to the residence of
Neaufles-Saint-Martin, located near
Gisors, which her husband had granted her as her dower land. She devoted herself to the education of her daughter Joan, whose marriage contract with
Infante John, Duke of Girona, son and heir of King
Peter IV of Aragon, was signed on 16 July 1370; unfortunately, the princess died on 16 September 1371 in
Béziers on her way to
Perpignan to celebrate her wedding. Blanche's retirement did not prevent her from temporarily returning to the court of King John II, whom she tried to bring closer to her brother King Charles II of Navarre. Thus, after the assassination of
Charles de la Cerda on 8 January 1354, she persuaded the French monarch to sign the
Treaty of Mantes with the King of Navarre on 22 February of the same year. Blanche had an influential presence under the reign of King Charles VI of France. On 2 October 1380, she attended the proclamation of the end of the regency of the young sovereign at the
Palais de la Cité, and on 18 July 1385, she welcomed his new wife
Isabeau of Bavaria at
Creil. Blanche was charged with teaching the new Queen the traditions and etiquette of the French court. On 22 August 1389, she organized the
Joyous Entry of Queen Isabeau in Paris, which preceded her coronation the next day. During the coronation ceremony in
Notre-Dame Cathedral in
Paris, Blanche attended on Charles VI, along with her cousin Princess
Blanche of France, Duchess of Orleans, youngest daughter of King
Charles IV of France and Joan of Évreux. After this ceremony, Blanche withdrew to Neaufles-Saint-Martin and died on 5 October 1398, aged 67. She was buried in the royal necropolis at the
Basilica of Saint-Denis next to her daughter. Her tomb, like many other royal ones, was desecrated on 17 October 1793 by the revolutionaries. ==In literature==