Isabella was born in 1337 as the daughter of James III of Majorca and his first wife, Constance of Aragon. She had an elder brother James. Her father remarried after her mother died in 1346 to Violante of Vilaragut. Through this marriage, she had a short-lived half-sister named Esclaramunda. Her father lost the Kingdom of Majorca in 1343, and he had died in the Battle of Llucmajor in 1349.
Isabella, her brother and stepmother, were captured by King Peter IV of Aragon after the battle. Peter was also her uncle. She and her stepmother were confined to the Convent of the Clarissans in Valencia. They were held there for ten years and were finally released after she was made to renounce her claim to the Kingdom of Majorca. Not much is known about those ten years in the convent.
Shortly after being released she was married to John II Palaiologos, Marquess of Montferrat in Montpellier. This marriage was arranged by her stepmother. Together they had four sons and a daughter. Her brother James died in 1375 in a desperate struggle against Peter IV of Aragon. He was defeated once more and died of either poison or an illness. That same year Isabella married again, having lost her first husband three years previously. Her new husband was Konrad of Reischach and Jungnau. It was a secret marriage, perhaps due to Konrad’s low status. The marriage produced a son, but they later separated.
Her children were not particularly interested in continuing to claim the Kingdom of Majorca, and therefore Isabella is considered to be the last active claimant to the throne of Majorca. She died in Montpellier around 1406.