Sharing a pic of herself from behind, wearing a black-and-white checkered one-piece bathing suit, the Younger star celebrated her "flaws" and encouraged women to be "proud of what we've got."
"I am posting this on behalf of young girls, women, and mothers of all ages," Duff wrote on Instagram on Friday. "I'm enjoying a vacation with my son after a long season of shooting and being away from him for weeks at a time over those months. Since websites and magazines love to share 'celeb flaws' - well I have them! My body has given me the greatest gift of my life: Luca, 5 years ago. I'm turning 30 in September and my body is healthy and gets me where I need to go.
"Ladies, let's be proud of what we've got and stop wasting precious time in the day wishing we were different, better, and unflawed," she continued. "You guys (you know who you are!) already know how to ruin a good time, and now you are body shamers as well. #kissmyass ?✌?."
Earlier this week, paparazzi snapped the actress paddleboarding and hitting the beach in Hawaii. She also took to social media to share silly pics with her gal pals from her vacation. Duff has been relaxing as much as she can after filming the fourth season of her TV Land show, Younger.