She was the eldest daughter of Alderano I Cybo-Malaspina [it] (1690-1731), Duke of Massa and Prince of Carrara, and his wife, Countess Ricciarda Gonzaga di Novellara [it] (1698-1768).

She hoped to officially inherit her family's County of Novellara and Bagnolo, an imperial fief left vacant upon the childless death of her brother Filippo Alfonso Gonzaga [it] and temporarily entrusted to her administration.

[8] When Maria Teresa turned twelve in the same year 1737, the Emperor insisted again: Ricciarda's uncle, Marquis Carlo Filiberto II d'Este-San Martino [it] (1678 –1752), was instructed to go to Massa and reopen negotiations on behalf of Francesco III d'Este, Duke of Modena, father of the groom.

For his part, the Duke of Modena undertook to increase by twenty thousand scudi, with his own funds, each of the dowries established for Maria Teresa's two younger sisters by their late father.

The wedding was celebrated by proxy in Massa on 16 April, with Maria Teresa's great-uncle, Carlo Filiberto d'Este-San Martino representing her husband.

[12] He made public displays of contempt towards her, threatening to send her back to Massa, and asked her to have their marriage annulled, saying 'Look, I understand that you are not for me and I am not for you, so tell the Duke that I will be content'.

The Duchess reported these words to her great-uncle, complaining of her treatment: Thus, I have lost my nerve in this: in any case I intend to try, obliging him with a world of niceties, and, if I do not even succeed in this way, I would then beg your assistance in dissolving this marriage.

I pray you convey my regards to the Marquise and your little ladies, to whom I wish a better fate than I have had, and again I recommend myself with all reverence.In June 1744, having reached the age of majority, she was invested as ruler of the Duchy of Massa and Principality of Carrara by Emperor Charles VII[13] and took over ruling from her mother,[14] who continued to assist her during her absences until her death in 1768.

'I will tell you', Maria Teresa wrote to her father-in-law in December 1746, 'that I am very happy with the prince, as he has completely changed and has modified his manners [...] You will have the consolation when you come of seeing us get along together in very good harmony'.

[20] Maria Teresa distanced herself from the court, visiting her Tuscan states in the summer and withdrawing often to Reggio, the second capital of the Este duchies,[21] where she reside in the Palazzo della Cittadella.