In 1794 her father participated in the military struggle for Polish independence and was mortally wounded at the Battle of Maciejowice, leaving behind a widow, seven children (five of them surviving into adulthood), and a dwindling livelihood.
At the age of eighteen she was married by her mother to the sixty-eight-year-old Athanasius, Count Colonna-Walewski, a wealthy landowner, starosta of Warka district and a once-chamberlain to the last Polish king, Stanisław August Poniatowski.
Walewska was being advised to work towards a position in the inner circle of Napoleon by the Emperor's aide, General Géraud Duroc (Grand Marshal of the Palace).
It was all about harvesting fruit now, achieving this one single equivalence [convincing Napoleon to support the Polish independence movement], which could excuse my debased position.
As Maria was extraordinarily discreet for her times, they still maintained apparent secrecy: she refused to leave the part of the building in which they lived, fearing being seen by officers surrounding Napoleon, many of whom were her acquaintances or relatives.
[6] According to Madame de Rémusat: This extraordinary wooing did not, however, prevent the young Polish lady [Marie] from becoming attached to the Emperor, for their liaison was prolonged during several campaigns.
She settled in a palatial residence in the Rue de Montmorency and was given a large rent of 120,000 francs and a permission to enter all of the imperial museums, but her relationship with Napoleon ended.
Though Marie Walewska was since presented at the Imperial Court, initially provoking the jealousy of Joséphine, after the divorce she became an intimate friend of the former Empress at Malmaison, frequently bringing her son.
On 15 June 1812, at Königsberg, East Prussia, Napoleon signed the letters patent, officially recognizing Alexandre with the title of Count of the Empire.
As a settlement, she and her oldest son received half of Count Walewski's estates, which even though heavily indebted, represented considerable wealth.
Upon request from her Polish relatives her body was exhumed from Père Lachaise Cemetery in Paris and moved to her family crypt in Kiernozia.
The first scholar to write a complete account of her life was a French biographer Frederic Masson, who was allowed by d'Ornano family to use her memoirs.
In the 1930s her adventures were once again described by her descendant, Antoine Philippe Rodolphe, 4th count d'Ornano in a book entitled Marie Walewska, "l'épouse polonaise de Napolėon".
It was a belletristic biography that until the mid-20th century was considered as a key source on Walewska, as Antoine d'Ornano claimed that it was based on never published documents remaining in the archives of La Branchoire, the family castle.
His book claimed that she was involved in taking major political decisions related to the development of Duchy of Warsaw and engaged herself in disputes with figures such as Józef Poniatowski or Joachim Lelewel.
Biographer Marian Brandys attempted to deal with some of these doubts in his book The troubles with Lady Walewska and he went as far as questioning the very existence of documents from La Branchoire.
His main argument was that the facts presented in the book were unrealistic in light of broader historical knowledge about Napoleonic campaigns and the politics of the Duchy of Warsaw.
The dispute revolved around copyright issues: Savant allowed the publication of extracts from his work, which included alleged excerpts from Maria's own accounts, taken from d'Ornano's book.