Bernice, who has links to a number of the local residents including ex-husband Ashley Thomas (John Middleton), returns to screens on Tuesday, November 20 as she arrives at The Woolpack unexpectedly.
Speaking to Soaplife, Giles tipped Bernice to ruffle feathers as she aims to spend more time with her daughter Gabby, who is already struggling with Ashley's split from Laurel (Charlotte Bellamy).
Giles explained: "Bernice thinks she'll just show up and everything will be fine with Gabby. She hasn't thought about the hard time Gabby's had recently, the breakdown of Ashley and Laurel's relationship and the stuff with Marlon. It must be very confusing for Gabby."
She continued: "Obviously Bernice has stayed in touch with Ashley over the years when they've done the exchanges with Gabby. But I think Bernice still finds him to be a bit pious. She tends to treat him as a bit of a joke, which irritates him."
The actress said that Laurel may also find it difficult to see Bernice spending time with Gabby.
Giles commented: "Bernice isn't being intentionally horrible or meaning to step on anyone's toes, but it just hasn't occurred to her that this is a serious issue for Laurel. She's always been rather patronising and dismissive towards Laurel because she sees her as this cleaner, which is what Laurel did when Bernice first met her."
When Bernice arrives back, she makes it clear that her marriage is in serious trouble - and as show bosses have recently cast her new lover Steve Harland, it appears that she may have been having an affair.
Giles teased: "She always used to leave a trail of disaster behind her and she hasn't changed one bit. Bernice is just as bad as she always was."