Described as having been a "frivolous and high-spirited princess", she also, at an early age, had displayed a tendency to be both stubborn and unyielding. In 1541, when Jeanne was 13, Francis I, for political reasons, forced her to marry William "the Rich", Duke of Jülich-Cleves-Berg, who was the brother of Anne of Cleves, the fourth wife of Henry VIII of England. Despite having been whipped into obedience, she, nevertheless, continued to protest and had to be carried bodily to the altar by the Constable of France, Anne de Montmorency. A description of Jeanne's appearance at her wedding revealed that she was sumptuously attired, wearing a golden crown, a silver and gold skirt encrusted with precious stones, and a crimson satin cloak richly trimmed with ermine.
This political marriage was annulled four years later on the grounds that it had not been consummated. She remained at the royal court.