Kylie's friends and fans shared their excitement in the comments, as they all celebrated Archie and his newfound independence.
Sally Obermeder even quipped: "I’m not crying. You’re crying," to which Kylie replied back with: "@sallyobermeder we’re all crying !"
She then added: "@sallyobermeder actually Sal you’re crying cos you’ve still got at least 14? years of mums taxi ahead of you."
Kylie, who shares her sons Archie and Gus with her husband Tony, often takes to social media to gush about her boys, and recently celebrated their birthdays.
"The 2-for-1 birthday dinner," she penned. "Happy 17th to our Archie today. And to Gus who turned 19, three weeks ago in lockdown."
"We love you both so much. And we love the girls who love you," she added, referencing their respective girlfriends who were pictured in the family snap.
With the boys at the edge of their teenage years, Kylie might find herself with some rare free time, after previously admitting to Good Health that motherhood isn't something she takes lightly.
"My weekends and weeknights are full of the boys' sports events," she told the publication in 2019.
"Being a mum to teens is terrific, but it's busy. It's hard to keep up. It's a full-time job, coupled with my full-time TV job!"