Daughter to Irish immigrant parents Patrick Burns and Mary Neary, Elizabeth grew up in Newark, New Jersey. Her father passed away when she was ten years old. Her mother would die in 1907. 

Elizabeth graduated with honours from Bellevue Hospital, New York and then specialised on maternity and childhood care. In 1906 she was employed by Frederic Oakley Spedden and Margaretta Corning Spedden to act as nursemaid to their young son Robert Douglas, who called her "Muddie Boons" because he could not pronounce Margaret Burns. 

She accompanied the family on their holidays, including to the Bermudas in 1911. The family were grateful to Miss Burns work, nursing the sickly young Robert and invited her on their three month vacation across Europe. 

The family's return was probably delayed due to the coal strike and they boarded the Titanic at Cherbourg. The group also included the family maid Helen Alice Wilson.

On the night of the disaster the party escaped the tragedy aboard lifeboat 3. Miss Burns made use of her nursing skills tending to the injured and shocked passengers on the Carpathia. She spoke of heroic deeds to the press and then it seems she left employment with the Speddens quite promptly after the disaster. The family were on holiday in both 1913 and 1914 and Miss Burns was not listed with them. Robert Douglas Spedden tragically passed away in a traffic accident in August 1915. 

Miss Burns was a member of the Red Cross executive committee of the New York County chapter during World War I recruiting nurses for the war effort. She would go on to be in charge of the industrial nursing department of J. H. Ladew Company, one of the largest leather manufacturers in the world. She travelled the world with the Ladew family.

Friends of Miss Burns thought that she never fully recovered from her experiences on the Titanic and her health declined She passed away in 1921 after an oedema of the lungs.