Luisa: EastEnders role made for me
The former Holby City star is joining the soap as Shirley Carter's sister Tina, a character that was tailored for her to play.
Luisa told the TV Times: "I'd never wanted to do EastEnders. I always thought, 'God no, I can't cope with that sort of fame'. But all of a sudden I got older and felt more chilled out.
"The casting director said she had me in as her wild card for Shirley's sister. The character was originally supposed to be an overweight 50-year-old who's past it. I turned up looking lovely to ask them if they had anything else, and they rewrote it for me."
She added: "It's such a good part. Tina is really funny and has some brilliant one-liners. She and Shirley spend a lot of time shouting, but there's real love there. They don't shout through anger, it's just what they do, and the next minute they're talking normally or giggling."
The 37-year-old actress arrives in Albert Square next week when it is revealed Shirley (Linda Henry) has been staying with her sister during her time away from Walford.
Shirley and Tina's brother Mick, played by Danny Dyer, is set to join them in Albert Square at Christmas.