Royals See Every Photo From Kate Middleton's Royal Baby Bump Debut! By Erin Hill Erin Hill Twitter Senior News Editor, PEOPLE People Editorial Guidelines Published on October 10, 2017 03:48 PM Share Tweet Pin 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. 01 of 07 Heathcliff O'Malley/Daily Telegraph/PA Wire After battling severe pregnancy sickness for the past month, Kate Middleton stepped out for the first time since announcing she is expecting her third child. 02 of 07 Heathcliff O'Malley - WPA Pool/Getty On Tuesday, the royal mom joined her husband, Prince William, and brother-in-law, Prince Harry, to mark World Mental Health Day at a special Buckingham Palace reception. 03 of 07 Heathcliff O'Malley - WPA Pool/Getty An aide told reporters, "The Duchess' condition is improving but she is still suffering from Hyperemesis Gravidarum. She is delighted to be able to be here tonight." 04 of 07 PA Images/Sipa USA The royal mom walked into The White Drawing Room with William and Harry in a pretty blue Temperley London dress, which showed off a hint of a baby bump. 05 of 07 Heathcliff O'Malley/Daily Telegraph/PA Wire The event marked Kate's first public outing since August 30, when she and the royal brothers marked the 20th anniversary of the death of Princess Diana. 06 of 07 Heathcliff O'Malley/Daily Telegraph/PA Wire Only a few days after that, it was announced that she is pregnant — and with that came news she was suffering from Hyperemesis Gravidarum, an extreme form of morning sickness that forced her to cancel her public duties. 07 of 07 Heathcliff O'Malley/Daily Telegraph/PA Wire Kate is understood to be less than four months pregnant – the palace made the announcement early because of her illness. Last time, when she was pregnant with Princess Charlotte, Kate was also cared for at home at Apartment 1A of the palace.