 She was daughter of John II (), Lord of Asti and Novara and imperial vicar, and Isabel of Majorca.Her father was son of Theodore I, marquess of Montferrat and Argentina Spinola; her mother was daughter of James III of Majorca and his first wife Constance of Aragon.Margaret was the only daughter of her father; her siblings were the marquesses Secondotto (, John III ( and Theodore II (.