She was the daughter of Count Stanislas Ernst von Dönhoff and Countess Maria Katharina Johanna von Dönhoff (1686-1723).

Konstancja was married to Prince Janusz Aleksander Sanguszko in 1731.

She lived separated from her spouse, who was homosexual and abandoned her shortly after the wedding.

In 1780, she remarried Józef Rogaliński, who abandoned her, wasted her fortune and left her to die in poverty.

She was involved in long lawsuits with both of her husbands which attracted great attention.