Lifestyle Travel Celebrity Vacations Ariana Biermann Models Mom Kim Zolciak-Biermann's New Swimwear Line in Instagram Bikini Pic Kim Zolciak-Biermann previously told PEOPLE that daughters Ariana and Brielle Biermann have been wearing the recently-launched swimsuits for months By Hanna Flanagan Hanna Flanagan Style + Beauty Assistant, PEOPLE People Editorial Guidelines Published on June 15, 2020 05:15PM EDT Photo: Ariana Biermann/instagram Ariana Biermann is all smiles in her new swimsuit. On Monday, the Don’t Be Tardy reality star, 18, posed with her husky in a series of Instagram photos wearing the white "Boardwalk" bikini set from her mom Kim Zolciak-Biermann’s new swimwear brand, Salty K. “🐶 🐶” Biermann captioned the post. Arianna’s 23-year-old sister, Brielle Biermann, wrote “Cutest angels♥️😻♥️👼🏻” in the comment section, while other Instagram users complimented the Bravo celeb on her new brunette hair and toned figure. Last month, Zolciak-Biermann, 42, told PEOPLE that Ariana has been focusing on her health and fitness — and "running her a-- off" — while social distancing amid the novel coronavirus pandemic (COVID-19). Ariana Biermann Dyes Her Hair Dark Brown as She Visits Her Stylist's Salon in Arizona Courtesy Kim Zolciak-Biermann The former Real Housewives of Atlanta star also revealed that her two oldest daughters were rocking Salty K swimsuits before the sustainable brand launched on June 1. In fact, Brielle and Ariana leaked two of the bikini designs in early May … without their mom’s permission! “Without me knowing, these bitches went outside to the pool and started taking pictures and posting photos in bikinis that aren't launching 'til the end of June!” Zolciak Biermann joked at the time. “I said, 'You can't post that Brielle. I don't want people to keep seeing these designs.’ The reality star continued, “[Brielle] was so mad, she said, 'I'm removing all my Salty K stuff from my Instagram! Why would you give me suits that you're not ready for me to take pictures in?' It was hilarious." Salty K. Brielle and Ariana Biermann Look Identical with Matching New Brunette Hair in Sister Selfie Speaking exclusively with PEOPLE, Zolciak-Biermann said the luxury swimwear line (which offers 10 styles total) is made entirely of recycled ocean plastics: "The sustainable luxury fabric is manufactured in Bali," 'she added. "These pieces are one of a kind." "There's a few things I'm passionate about — it's hair, makeup, skincare, bikinis and lingerie," the Don't Be Tardy star explained. "Lingerie, I don't ever want to design, I just want to own everything Agent Provocateur's ever made, which I do. But I don't want to design it. I'm not passionate enough to design it. But swimwear I want to design — I know how I want suits to look and fit. I have visions and sketches."