The 33-year-old former-Girls Aloud star invited her former bandmates Cheryl Fernandez-Versini and Nicola Roberts to be by her side on her big day.
Walsh also called her two best friends from home, her two sisters and her boyfriend Justin Scott's sister and daughter Chloe to be her bridesmaid, reported Female First.
"I know it's eight, but if you break it down there's no one who shouldn't be there. I either have hardly any or have them all, and there are no rules are there?" she said.
Walsh got engaged to her boyfriend of 11 years last year after they became parents t0 10-month-old son Bobby.