She is remembered as the editor of posthumously published editions of Emily Dickinson's poetry and letters and also wrote several novels and books about her travels with her husband, astronomer David Peck Todd, as well as co-authoring a textbook on astronomy.

[9] Todd and Dickinson were convinced that their love was above the morals of the day; Mabel once wrote that she thought things might have been different “had we been born one or two hundred years” later.

[3] Todd had been concerned over moving to a small town, as her life might not be as exciting as it had been in cosmopolitan Washington or Boston, but she soon found ample outlets for her energies.

She joined the church choir, was active in local theatrical performances, and her diaries are full of accounts of activities – "coaching parties to Mount Toby or Titan’s Pier, sugaring-off parties, bowling and archery contests, horseback riding – one June morning she speaks of riding to Leverett before breakfast – and even tobogganing".

[10] She accompanied her husband David when he traveled to Japan in 1887 to photograph the solar eclipse, and she was the first Western woman to walk up Mount Fuji.

[11] She accompanied David in his other efforts to photograph eclipses, traveling with him back to Japan in 1896, to Tripoli in 1900 and 1905, to the Dutch East Indies in 1901, to Chile in 1907, and to Russia in 1914.

[20] From 1890 to 1913 she went on regular lecture tours up and down the east coast, as far south as Florida and as far west as California, talking about her travels and other topics of interest.

[21] By 1917, David's deteriorating health and erratic mental behavior caused Amherst president Alexander Meiklejohn to force his early retirement from the College, and the couple moved to Coconut Grove, Florida.

[22] Mabel and their daughter Millicent made the decision to institutionalize David in 1922; for the remainder of his life he was in and out of different mental and care facilities.

Mabel continued to advocate for civic causes, especially preservation of nature and the wilderness; she was one of the people involved with the creation of the Everglades National Park, and the island she owned in Maine - Hog Island (Lincoln County, Maine) - was donated to the Audubon Society by her daughter, saving it from development.

When Susan's work didn't quickly move the publication project forward—Susan wanted to publish the poems in a holistic volume contextualized with Dickinson's letters, jokes, manuscripts, and drawings, a publication that would be very unconventional for the time but perhaps more authentic to Dickinson's writings[29]—Lavinia enlisted Todd and Thomas Wentworth Higginson.

Emily's younger sister Lavinia, who controlled the copyright of the poems, wanted to give royalty payments to Todd herself instead of having the publisher divide proceeds.

Austin had left Todd and her husband a strip of his land and Lavinia had begun the process to make it legal before changing her mind and suing them in 1898 for the claim.

[34] Todd, upset at the rival publications and assuming only she had legal rights to Emily's works, released an updated edition of her compilation in 1931.