Celebrity Celebrity Moms Olivia Wilde Reveals Her Baby's Gender Over Twitter By Lara Walsh Lara Walsh Lara Walsh is a Chicago-based writer and editor who covers all things fashion, celebrity, pop culture, travel, and food. When she’s not avidly planning her next trip, she’s writing posts for her travel blog or mapping out her next foodie adventure. InStyle's editorial guidelines Updated on September 25, 2016 @ 01:30PM Pin Share Tweet Email Photo: Noam Galai/Getty Just hours after revealing that she and Jason Sudeikis are expecting a baby girl, mom-to-be Olivia Wilde was the picture of fall elegance walking the red carpet at the Global Citizen Festival in New York on Saturday. The actress rang in the new season by opting to wear a black fitted long sleeve sheath dress embellished with orange and purple autumn leaves to the music festival. The knee-length number hugged the star's burgeoning baby bump and made it the central focus of her colorful look. The 32-year-old beauty, who is already mom to two-year-old son Otis, kept the rest of her look clean and streamlined for the event. Chunky black rocker boots and a simple black watch finished off her red carpet ensemble, and the House star added a cat eye and pulled her brunette locks back into a topknot to put the focus on her glowing skin and cheekbones for days. Earlier that day, Wilde had revealed that her son Otis will have a baby sister with a tweet criticizing presidential candidate Donald Trump. "As someone who is about to have a daughter, this hits me deep in my core. #NeverTrump," she wrote alongside a short video clip from rival presidential candidate Hillary Clinton. Olivia Wilde Covers Up Her Baby Bump with Cute Overalls VIDEO: Olivia Wilde and Jason Sudeikis's Cutest Couple Moments We can't wait to meet the baby girl!