After Vidkun was found guilty of treason and sentenced to death, she made several appeals to authorities on his behalf but was unsuccessful.

After having lived a secluded life in Oslo after the war, she died in 1980, leaving her assets to a charity fund bearing her and Vidkun's name that each year gives a small sum of money to a limited number of elderly persons.

[5] Historians believe this is wrong, as Norway did not formally recognize the new Soviet authorities before 1924, and the representative at the Norwegian Commerce office did not have the right to perform marriages and was not in Moscow on 10 September.

Historian Hans Fredrik Dahl believes some kind of marriage took place in Kharkiv on that day, but he is unsure whether it happened in formally correct ways or was an informal ceremony.

[7] Quisling left Russia on her own and arrived in Paris, where in late 1923 she was reunited with Vidkun and Alexandra, who had travelled together.

[7] They lived for a time at Hotel Studia in the Latin Quarter,[8][9] though they travelled to Vienna and other places from November to January 1924.

[11] After Vidkun got a position in Moscow as legation secretary in charge of British Diplomatic affairs which was handled by Norway, she joined him there in November 1928.

[14][15] In December 1929, the couple settled in Oslo, where in 1922 Vidkun had bought an apartment in Erling Skjalgssons gate 26 in Frogner.

[16] Most of the 200 paintings were placed in safe deposit boxes, as they proved difficult to sell for the prices Vidkun had expected.

Construction of the building had begun in 1917, but was left uncompleted until the collaborationist authorities designated it a residence for the Quisling couple in the beginning of 1941.

Maria Quisling actively took part in the furnishing of the residence, which included Russian furniture and a large painting the couple had bought in Moscow.

[19] When Vidkun was appointed Minister President on 1 February 1942, a large celebration took place at Villa Grande, with Maria Quisling as hostess.

[21] After Vidkun was arrested in May 1945, Maria was without contact with him for two months when they were given permission to correspond and in August she visited him for the first time in prison.

His wife was deeply shocked and wrote letters of appeal to various authorities, including King Haakon, Prime Minister Einar Gerhardsen and Otto Ruge.

When Vidkun was informed on 23 October that his execution would take place that night, he wrote a last letter to her and included a lock of his hair which she kept.

The authorities gave her access to two rooms in Villa Maihaugen in Vinderen in Oslo which belonged to a man who was imprisoned for having cooperated with the German occupation government.

Several other wives of the NS leadership got rooms in the same house, and Quisling and the others attracted negative reactions from neighbours and the press.

"[29] In the article, the journalist wrote "Nobody has more supported the Germans and the Nazis than Mrs. Quisling and she benefited in all kind of ways during her man’s time in power.

[31] The prosecutors dropped the charges of encouraging armed resistance, but she was charged with having been a member of NS, for having represented the occupation regime in her position as Vidkun's wife, for having encouraged Vidkun to use public funds to decorate their homes, and for having received goods the occupation regime had confiscated from the royal palace.

[35] The division of Vidkun and Maria's joint spousal effects (Norwegian: fellesbo shortened bo) was handled by the Erstatningsdirektorat (Compensation directorate).

There were huge assets in the bo, but also great liabilities in the form of compensation claims related to Vidkun's actions during the occupation.

In her later years she was visited by a woman from Oslo Inner Mission Society[44] and when she was hospitalized, she had regular visitors from the Catholic Church.

[45] In 1976, she decided in her will that her assets after her death should fund an endowment, Vidkun og Maria Quisling's legat,[46] later called Maria Quislings legat, which should be administered by Oslo Inner City Mission and each year give economic help to elderly people in dire economic situations.