Ma, while on expedition against the Wulin tribes (in modern eastern Guizhou and northwestern Hunan), died during the campaign from a plague, which also killed a large number of his soldiers.
Two specific accusations that are known are that Ma, by the route he took against the Wulin tribes, was responsible for the plague, and that he had, while on campaigns, embezzled pearls and rhinoceros horns.
(The later accusation was a misunderstanding in that one of Ma's favorite foods—which he considered capable of warding off plagues—was Job's tears (Chinese pearl barley), which was produced in southern China and northern Vietnam, which Ma had transported in large quantities back to the capital Luoyang.)
The Dous began to have second thoughts of the marriage, believing that Lady Ma was no longer worthy to marry their son.
In 71, as mass tortures and executions were being carried out as a result of a conspiracy engaged in by Emperor Ming's brother Liu Ying, the Prince of Chu, Empress Ma interceded on the accused people's behalf, and as a result, Emperor Ming tapered off on his efforts to eliminate anyone who might be even remotely connected with the conspiracy.
Empress Ma objected—she did not understand why these principalities were only half as large as the ones for Emperor Guangwu's sons.
Empress Dowager Ma also established a textile factory and a mulberry garden for silkworms, which became a fairly productive industry for the imperial household.
In her spare time, she often discussed important matters of state with Emperor Zhang and taught his sons the Confucian classics – particularly the Analects of Confucius.
In 79, over Empress Dowager Ma's objection, Emperor Zhang created his uncles marquesses.
However, under pressure from the empress dowager, the new marquesses, after their requests to decline the fiefs were denied by Emperor Zhang, resigned their government posts.