Between 2012 and 2017 Spence played for . After Spence attended an Irish Exiles trials in August 2011, Philip Doyle decided to fast track her into the Ireland team. Doyle recognised her potential and was keen to claim her for Ireland before came calling. She subsequently made her debut for Ireland on 3 February 2012 against . The match was abandoned at half-time because of a frozen pitch. Spence went on to represent Ireland at the 2014 and 2017 Women's Rugby World Cups. Spence was a member of the first Ireland teams to defeat and . She was also a member of the Ireland teams that won the 2013 and 2015 Women's Six Nations Championships. In 2015 she was a nominee for the IRB Women's Player of the Year, the RTÉ Sports Person of the Year and was named the "Guinness" Rugby Writers of Ireland Women's Player of the Year. Spence retired as an Ireland international after failing to make the squad for the 2018 Women's Six Nations Championship.