Wallace was given a makeover for her part in "Redwater", different to how Kat looks in "EastEnders". Wallace explained that Kat's different look is because she has "mellowed" since leaving Walford and travelling to Spain, which she described as a "softer side to Kat than we've seen before", but said she still has a "fiery side to her, just not as much as we've seen in "EastEnders". Wallace described Kat as a "colourful person" with "a lot of layers to her" and said that after playing her for 16 years "means there's plenty underneath to bring to the surface." She said that Kat wants "peace and to settle down with no more drama in her life." In the series, the character is called "Kathleen" by all characters except Alfie, who calls her "Kat".