Smurfit married advertising executive Douglas Baxter on 29 July 2000, and gave birth to her first child, daughter Evie Dorothy Baxter in Dublin, Ireland on 2 November 2004. A second daughter, Ridley Belle Baxter was born in May 2007. Their third child, a boy, was born in November 2008 and named Flynn Alexander Baxter.
In February 2015 it was announced that Smurfit and her husband had filed for divorce.
She writes an opinion blog for The Dubliner, which often features anecdotes from her personal life. and is a patron of the children's charity World Vision Ireland.