Before she became a nurse, she was a school teacher in Richmond, Virginia, and then in the 1890s, she went to New York, to study elocution and speech at Cooper Union.

[6] She then studied nursing at the Women's Infirmary and School of Therapeutic Massage, graduating in 1900 as the only black woman in a class of thirty.

[6] In the first part of the 20th century, Thoms worked with Martha Minerva Franklin and Mary Mahoney to organize the National Association of Colored Graduate Nurses.

[5] Thoms was received at the White House by President and Mrs. Warren G. Harding in 1921, during the National Association of Colored Graduate Nurse Convention in Washington, D.C.[5] In 1923, she remarried, to Henry Smith, who died within the year.

[6] In 1908, Adah met Martha Minerva Franklin, who at the time was striving towards holding a conference for 52 graduate black nurses.

Franklin wanted the support of Lincoln School for Nurses Alumnae Association, who eventually sponsored the meeting.