News Kate Middleton Debuts Baby Bump in First Public Appearance Since Announcing Pregnancy By Olivia Bahou Olivia Bahou Facebook Olivia Solomon is a New York-based writer and editor who covers all things fashion, lifestyle, celebrity, and pop culture. She was previously the Assistant Digital Editor for InStyle, and her work has appeared in many national publications. InStyle's editorial guidelines Updated on October 10, 2017 @ 02:15PM Pin Share Tweet Email We independently research, test, review, and recommend the best products—learn more about our process. If you buy something through our links, we may earn a commission. Kate Middleton has made her first public appearance since Sept. 4, when she announced her third pregnancy, and the elegant maternity style she debuted was certainly worth the wait. The Duchess of Cambridge, who has been bedridden with Hyperemesis Gravidarum or severe morning sickness, stepped out for a reception in honor of World Mental Health Day on Tuesday, showing off her tiny baby bump. PA Images/Sipa USA Middleton looked radiant in a light blue lace Temperley London dress ($875; net-a-porter.com) with long sleeves, a waist-defining silhouette, and a mid-calf length. She paired the dress with her classic blowout and black pointed-toe pumps, her baby bump just visible underneath her frock. PA Images/Sipa USA The mom of two joined husband Prince William and brother-in-law Prince Harry at the event in Buckingham Palace to meet with and honor those working in the mental health sector. “The Duchess’s condition is improving but she is still suffering from Hyperemesis Gravidarum. She is delighted to be able to be here tonight,” an aide told reporters, according to People. Tuesday marks Middleton’s first public appearance since Aug. 30, when she stepped out to mark the 20th anniversary of Princess Diana’s death. While the Duchess was present at Tuesday night’s reception, she wasn’t in the audience earlier in the day when Prince William gave a speech to celebrate the impact of their mental health awareness organization, Heads Together, in which he revealed that it was his wife who came up with the idea. “It was Catherine who first realized that all three of us were working on mental health in our individual areas of focus. She had seen that at the core of adult issues like addiction and family breakdown, unresolved childhood mental health issues were often part of the problem,” William said of the organization’s start. Kate Middleton Is Trying an Old-Fashioned Remedy to Combat Morning Sickness “We decided to assemble a coalition of charities—comprised of people who had spent decades working to bring mental health out of the shadows—to campaign together to change the national conversation on mental health.” As this soon-to-be mother of three prepares to welcome her new addition, she continues to do her part to erase the stigma surrounding mental health issues.