Popsugar Entertainment Halloween 40 Best Sister Costume Ideas For Halloween 2023 40 Best Sister Costume Ideas For Halloween October 6, 2023 by Maggie Panos First Published: October 1, 2015 View On One Page Photo 6 of 41 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 6 Sister Halloween Costumes: Marcia, Jan, and Cindy Brady From "The Brady Bunch" What to wear: Dive into some sweet '70s duds! Think colorful or striped shirts and slacks. If you're Cindy, high pigtails are the key. How to act: Marcia is cool and confident, Jan is super jelly of Marcia, and Cindy is just getting into trouble somewhere. Previous Next Start Slideshow HalloweenHalloween CostumesPop Culture Halloween CostumesTVMovies