Margaret (3) Emmet was five years old when the British arrested her father and sent him to jail with others involved in the Uprising of 1798. With her brother Robert (2) and sister Elizabeth (4), she went to Scotland with her mother in 1800, living in the Ft. George prison for two years, where Thomas (1) Addis Emmet (TAE) was sent from Kilmainham Gaol in Dublin. It is said that even though only a small child, her "cheerful companionship did much to mitigate the severity of her father's punishment." Her father's letters to his mother in Dublin described her as "displaying an early and judicious capacity." She remained with her parents in exile in Europe and on their voyage from Bordeaux to New York in the fall of 1804.
As a young woman in America, Margaret was very involved with all members of her family, weeping when her sister Jane (8) left the family house to marry. She often visited Elizabeth (4) LeRoy in Potsdam, NY, where a young doctor was interested in her; they went on long rides through the countryside together and he was quick to enjoy her pound cake. Her older brother Robert (2) noted in a letter that when she returned, he noticed an improvement - she was "more clarified, more springy and more substantial than before." She traveled to Virginia several times to see her brother, John (5) in Charlottesville; during one visit, she wrote: "John and I get at the piano sometimes in the evening and play 'till all is blue, and I believe we pass for music-mad.... I am a lion for execution and every now and then I hear of someone who wants to come and 'hear Miss Emmet play.' " Her skillfull playing of the piano was something she kept doing until well into old age. She was an excellent rider, who could comfortably go twenty miles in a day. A good cook, she helped her mother keep house both in the City and at the Emmet family country place. Her letters describe her interest in fashion: "Brown silks are the rage now and I have got a very handsome one (1823)." She lived with her sister and brother-in-law, Mary Anne and Edward Graves, after her parents died.
In 1842, she traveled to Ireland with her sister Mary Anne (10) to see the remaining relatives there. She wrote frequently, describing her mother Jane's brother, John Patten, and various Colville cousins. John lived about two miles outside Dublin in a house called "Sandy Mount," where "we are treated like spoiled children and nothing can exceed the kindness of all." The group went to see cousins in Killarney and Limerick, Margaret commenting that "it is delightful to see how affectionately Mama is remembered." They later traveled through the North of Ireland and on to Scotland before sailing for home - the first Emmets to return to Ireland since their uncle Robert was executed in 1803.
Margaret's brothers made a point of introducing her to various eligible men, and several were "smitten" by her, but apparently she had no interest in marrying any of them. When John (5) and his new wife, Mary, were setting up their house on the UVa campus, she and Mary Anne (10) were involved in sending them wallpaper samples and making other suggestions for fixing up the interior. Said to be a "shrewd observer," she was always direct and liberal in her transactions. She remained single and died peacefully of old age on March 1, 1883 in her 90th year, while staying with her great-nephew and his wife, Mr and Mrs. Bache (92) McEvers Whitlock at 10 West 37th Street. According to the NY Times of March 4, 1883, her death "was very peaceful and occurred in the midst of nearly all her relatives." Her funeral was held at the Calvary Protestant Episcopal Church in New York and Margaret was buried in the Beechwoods Cemetery in New Rochelle, NY with other family members.