On her mother's death in 1205, Maria became Queen of Jerusalem, aged 13. Her mother's half-brother John of Ibelin, Lord of Beirut, acted as regent for Maria.
On September 14, 1210, Maria married John of Brienne (c.1150 – 1237) in Acre in an arranged marriage. Their daughter Yolande of Jerusalem (also known as Isabella) was born in 1212, but Maria died shortly after. John became regent for his daughter Yolande, now Queen of Jerusalem.