Maria was born in Iasi as the daughter of the Moldavian Prince Dimitrie Cantemir. She was very well educated. From 1711, she lived in Russia, and in 1720, she became involved in a relationship with Emperor Peter. Maria followed Peter to Astrakhan in 1722, where she gave birth to a son by him. The child died in 1723, possibly poisoned by the physician of Empress Catherine. Catherine regarded Maria as a threat and was afraid of being replaced as empress by her. The relationship with Peter continued until his death in 1725, when she was forced to leave court. She was a lady in waiting to princess Natalia in 1727–28 and to Empress Anna Ivanovna in 1730–31. After this, she hosted a literary salon in Saint Petersburg.
She is also mentioned in the autobiography of the Swedish slave Lovisa von Burghausen. Burghausen was the prisoner of Dimitrie Cantemir in 1713-1714, and credited Maria and her sister Smaragda with saving her from freezing to death during a punishment, by allowing her to sleep in their bedroom instead of in an unheated stone room in the middle of winter.