By the 2340s she was married to a Human male, John Torres. John married Miral because he "loved [her] intensity," and though John's mother also loved Miral, she also warned him not to marry her because, according to John, "she never thought I had the constitution to live with a Klingon." (VOY: "Lineage")
In 2354, when B'Elanna was about five, John revealed to his brother Carl that B'Elanna was becoming "moody, unpredictable, argumentative," just like Miral. He noted that their marriage had reached a point that "everything's become a fight" with Miral, and the older John got, the less of her intensity he could handle. B'Elanna, who had overheard the conversation, accused John of not loving her and Miral any more. Though he initially denied this, he abandoned his wife and daughter twelve days later. (VOY: "Lineage")
After the two separated, John returned to Earth, while Miral and B'Elanna returned to Qo'noS, where Miral still lived as of 2371. At that time, she and B'Elanna were out of touch because they did not get along well. (VOY: "Eye of the Needle")
Nearly twenty years later, in 2376, when B'Elanna lapsed into a coma after her shuttle was hit by an ion storm, she found herself on the Barge of the Dead on her way to Gre'thor (the Klingon version of Hell). During the trip another dishonored soul appeared to her: her mother, Miral, who, according to Klingon religious beliefs, had to pay for the sins of her daughter. When B'Elanna awoke, she was determined to save her mother. She convinced Kathryn Janeway to let the The Doctor put her back into a near death coma. (VOY: "Barge of the Dead")
B'Elanna arrived again on the Barge and tried to perform a ritual that would send Miral to Sto-vo-kor. It failed and B'Elanna realized that the only way to save Miral was to die for her and take her place in Gre'thor. She did this and Miral ascended to Sto-Vo-Kor, as B'Elanna was led into Gre'thor. (VOY: "Barge of the Dead")
Miral then appeared to B'Elanna again, telling her that she could be saved if B'Elanna lived with honor. Just then, The Doctor woke B'Elanna from her coma. Before being revived, Miral told B'Elanna that she may see her when she joined Sto-Vo-Kor herself, or when she returned home to the Alpha Quadrant. (VOY: "Barge of the Dead")
When B'Elanna spoke with her father, in 2378, for the first time in twenty years, they discussed among other things, B'Elanna's pregnancy. When he asked what they planned on naming the child, and she told him "Miral", he told her that "your mother would've liked that." (VOY: "Author, Author")
Miral hinted that she could possibly still be alive at the end of the episode "Barge of the Dead", however, John spoke of her in the past tense when she was referenced in "Author, Author", suggesting otherwise.
The possibility of Miral being alive was followed up in the Voyager relaunch novels, in which B'Elanna returns to the Klingon colony of Boreth, where she finds her mother alive.
Her mirror universe counterpart (β) was depicted as the Intendant of Earth in the novels The Mirror-Scaled Serpent and Rise Like Lions. She was given that assignment in 2368 as punishment for spurning the "crude advances" of Worf, the then-regent of the Klingon-Cardassian Alliance.