She was scarcely two years old when her mother brought her to the convent of Aldenberg, where she afterwards became a nun. In 1248, only twenty-one years old, she was elected Abbess, and ruled over the convent for forty-nine years.
With the inheritance she received from her uncle, Dietrich I, Margrave of Meissen, she erected a church and a poorhouse. She took personal charge of the inmates of the poorhouse and led a life of extreme mortification. When Pope Urban VI published a crusade against the Saracens, Gertrude and her nuns took the cross.
In 1270 she began to observe the feast of Corpus Christi in her convent, being one of the first to introduce this feast into Germany. Pope Clement VI permitted the ecclesiastical celebration of her feast to the convent of Aldenberg and granted some indulgences to those who visited her relics.