This portrait appears after a portrait of her daughter Élisabeth, but this portrait shows an elderly Françoise. According to her Wikipedia article, her husband died in 1665.
Françoise is dressed somberly and plainly, very much like a nun, in this portrait.
Keywords: 1667, Françoise of Lorraine, Lorraine family, Bourbon family, Princess, Duchess, French, long coiffure, attifet, veil, high enclosing neckline, capelet, long puffed sleeves, cuffs, mourning dress