In addition to her career as a patron of the arts in Berlin, she is known for editing and publishing the work of her husband Carl von Clausewitz, especially his military treatise On War.

Her paternal grandfather was Polish-Saxon statesman Heinrich von Brühl, while her mother was an aunt of the British field marshal William Maynard Gomm.

[2] When Fanny died in March 1804 due to complications during childbirth, Marie was left to care for the orphaned daughter.

He taught Marie how to write and read in French, and how to compose letters in a manner appropriate for a "lady of high society.

[13] Brühl met Carl von Clausewitz in December 1803 through their mutual friends, Princess Louise and her husband Prince Antoni Radziwiłł.

[14] Their meeting came less than a year after Brühl's father's unexpected death due to complications from liver disease in July 1802.

[20] In August 1810, Clausewitz received an important letter from Friedrich Wilhelm that promoted him to the rank of major, and gave him official permission to marry.

In the summer of 1832, less than a year after Carl's death, a publishing house in Berlin had put out announcements advertising the upcoming publication of On War.

Along with her responsibilities as chief lady-in-waiting, von Brühl also put pressure on herself to publish her deceased husband's works.

Her cousin Carl von Brühl insisted on moving her to Dresden to salvage what was left of her health.

Due to the lack of knowledge about modern medicine and infections, the doctor in Dresden simply diagnosed Marie with damaged nerves and ceased treatment.

[25] Her portrait of Prussian Field marshal August Neidhardt von Gneisenau is in the collection of Deutsches Historisches Museum.