Scullin was born in Ballarat, Victoria, to Sarah (née Simcocks) and Michael McNamara.

She married James Scullin at St Patrick's Cathedral, Ballarat, on 11 November 1907.

[3] When her husband became prime minister in 1929, the couple chose to live in the Hotel Canberra rather than The Lodge, as an economy during the Great Depression.

[4] She nursed him during his bouts of ill health, and during the four-hour "sickroom cabinet" meeting of August 1930 "stood guard at the door, refusing entrance to all unwanted visitors".

She was buried alongside her husband in the Catholic section of Melbourne General Cemetery.