The actress's alter ego made a surprise comeback in mysterious circumstances last month, but viewers have since discovered that she is in a relationship with fellow returnee Warren Fox (Jamie Lomas) and is helping him with his sinister schemes.
Speaking to the Manchester Evening News, Dunn commented: "At the moment she's come back and she's causing loads of trouble. It's quite nice because they put a different spin on the character.
"When they asked me back they said, 'This is what the storyline is going to be', and I said, 'Brilliant, it sounds loads of fun'. It's totally unexpected, I think, for everyone watching."
Although Dunn will appear in a production of Peter Pan at The Lowry theatre in Salford throughout December, she said that her Hollyoaks filming commitments will resume in the New Year.
"I'm actually back for a little while again - I'll be returning after I've done the show at The Lowry next year as well," she explained. "So I'm looking forward to a few more storylines."