Born in Belfast, Northern Ireland,[1] Mawhinney was educated at Regent House School, Newtownards.
She was the duty presenter in the early hours of 31 August 1997, when news broke of the fatal car crash of Diana, Princess of Wales.
Mawhinney presented in various timeslots on the channel, including a period in the afternoon slot alongside Matthew Amroliwala and Chris Eakin, before being assigned to Sunday afternoons in April 2006.
[7] She had two younger sisters, Alexa and Lorraine, who died from skin cancer.
[8] She was diagnosed with breast cancer in November 2013;[2] she underwent surgery, drug therapy and radiotherapy, and was back in the studio in March 2014.