Margery De Badlesmere (1306-1366) was the eldest sister and co-heir of Giles, Baron Badlesmere of Leeds Castle, county of Kent. She survived her husband, William Ros, by many years and was one of the very few English people present at the Jubilee, at Rome, in 1350; King Edward III of England had tried to prevent the attendance of his subjects at this ceremony on account of the large sums of money usually taken out of the kingdom on such occasions. Their children were:
• William de Ros, 4th Baron de Ros
• Thomas de Ros, 5th Baron de Ros
• Sir John De Ros
• Margaret de Ros
• Matilda de Ros