Catherine was betrothed to Charles, Count of Charolais, the Burgundian heir, in accordance with the Treaty of Arras between France and Burgundy from 1435. In 1438, Charles visited the French court with an embassy and formally proposed to Catherine. On 11 June 1439, the couple was officially betrothed at St. Omer, and on May 19, 1440, the wedding was conducted at Blois. The bride was aged 12, the groom 7. They had no children. Reportedly, Catherine and Charles had a friendly relationship, but due to her youth, Catherine did not live with Charles but was handed over to the care of her spouse's mother Isabella of Portugal, Duchess of Burgundy, with whom she apparently got along very well, being treated like a substitute daughter.
Catherine was described as intelligent, kind and charming and was well liked in Burgundy, but the frequent travelling she was expected to do in parallel to adjusting to the formal court etiquette, which was required at the Burgundian court, described as one of the most elaborate in Europe and constantly moving about between the cities of the Low Countries in a cold climate, was reportedly exhausting for Catherine's delicate health. She fell ill with violent coughing in 1446 and died with what was likely tuberculosis.
References
Ruth Putnam, “Charles the Bold”
Aline S. Taylor, “Isabel of Burgundy: The Duchess Who Played Politics in the Age of Joan of Arc, 1397-1471”
Ancestry
Ancestors of Catherine of France, Countess of Charolais