O'Malley is the daughter of Barbara Marie (née Atkins) and former Maryland Attorney General J. Joseph Curran Jr.[3] A native of Baltimore, she attended Notre Dame Preparatory School.

[1] Upon graduation from law school in 1991, O'Malley accepted a job as an assistant state's attorney in Baltimore County, serving in that office until her appointment as a judge.

[4] On August 16, 2001, then-Governor Parris Glendening appointed her to a 10-year term, expiring in 2011, as an Associate Judge for the First District Court of Maryland, encompassing the city of Baltimore.

In her combined role as first lady, she welcomed judges' delegations annually from Saint Petersburg, Russia, to Government House for receptions and working dinners.

[8] In 2019, O'Malley joined the Open World Leadership Center Board of Trustees, supporting the organization's mission of promoting the rule of law and democratic values around the globe.