Agathe was the daughter of unknown parents. The date and place of her birth have not been found.
Her husband was Friedrich I von Schönburg. They were married, but the date and place have not been found. Their six known children were Dietrich I (?-c1317), Friedrich II (?-1299), Friedrich III (?-<1310), Agathe (?-c1280), Heinrich (?-1309) and Hermann IV (c1301-?).