She was hired around 1865 to teach mathematics at Vassar, within the Department of Mathematics, Natural Philosophy and Chemistry. When the head of the department, Charles Farrar, stepped down in 1874, Braislin became the chair of the newly formed Department of Mathematics, and appointed as an instructor of mathematics. In 1875 she was elected as professor of mathematics. She was the first professor in the department and the first female professor at Vassar, in addition to being (after
Susan Jane Cunningham at
Swarthmore College in 1871) one of the first female professors of mathematics in the US. She resigned in 1887, to marry Timothy Merrick, a wealthy businessman in
Holyoke, Massachusetts. She died of heart disease at her Holyoke home the following year. On December 18, 1888, her funeral was held in Holyoke. ==Legacy==