It was announced earlier this month that Harding, 33, would be joining the cast of the show for a guest stint over the summer.
While full details of Harding's storylines and character have yet to be revealed, she will be playing a "feisty troublemaker" who will make life difficult for Tracy Barlow, reported Digital Spy.
"I can't believe it. I found out a few weeks ago but it was in the pipeline for a while. "The producers know that I love the show. I do charity work with them and, at an event, they could tell I was a fan as I was going mental at the cast.