The 33-year-old is set to make her debut on the ITV soap later this year playing feisty Joni Preston, who will give villain Tracy Barlow a run for her money.
Joni is dating Tracy’s ex-husband Robert Preston and the two quickly come to blows.
Former Girls Aloud singer Sarah revealed that Joni gets to give Tracy a slap, telling the Express: “Every time They shouted cut I’d be giggling because Kate [Ford, who plays Tracy] was so lovely.
“It was not a real slap, it was all choreographed to look nasty but I didn’t actually touch her!”
But it’s not long before Robert realises just how much he’s missed Tracy, and the pair are soon locking lips.
Sarah added that, despite her tough exterior, Joni is a woman fighting to move out of somebody else’s shadow.
She continued: “[Joni] is very vulnerable at the same time, she does come across as very angry and feisty but she is also hurting – people have to remember that.
“If you catch your husband having an affair you would be, wouldn’t you?”
As well as being busy with Corrie, Sarah is gearing up to release her debut solo album and first single Threads is out next month.