"I posted that picture so innocently, and I get home and my mom is like, 'Oh my gosh! Sadie, I cannot believe you posted that. Are you about to get married? Why would you post that?'" the Duck Dynasty star recalls with a giggle. "I was like, 'I caught the bouquet! Of course I'm gonna post it!"
But don't expect this 18-year-old to be headed down the aisle too soon, even though she tells ET that she thinks boyfriend Blake is "the one."
"It's kinda fun to play with my Instagram followers because, I'm not kidding you, I can post a picture of, like, a lemonade or something, and they'll be like, 'Are you and Blake getting married?' It is anything! it could be the most random thing and that's all my comments," she says. "So I'm like, I might as well make them really start talkin'! It was really funny, we were just laughin’ at all the comments. But no, I'm actually still in high school so we are not about to get married."
The adorable couple has attended their fair share of weddings together already, and Sadie says that they do talk about sharing a future together.
"We've been long-distance our whole relationship, for two years, which is hard," she confesses. "So we're always like, 'Oh, I can't wait until we're finally just married and we get to be in the same place.' So that's just fun to talk about, but nothing serious."
"I can't wait to adopt," Sadie says. "I try to adopt when I go on all my mission trips. I'm like, 'Mom, please let me bring them home!' She's like, 'You're in high school, Sadie. Wait til you're married.' ... I'm gonna have too many -- I'm gonna have so many kids."
For now, Sadie has a full plate of her own. She's busy promoting her new fashion line for Wild Blue, walking in the Sherri Hill New York Fashion Week show, playing bridesmaid for sister Rebecca's upcoming destination wedding, and graduating high school this spring. Still, she'll make time to partake in the time-honored tradition of Prom.
"It's kinda funny because Blake, my boyfriend, plays college baseball, so he can't come [to prom]," she says. "So, my cousin, Cole, we're going together and we're just gonna be goofy and have so much fun. I'm really excited about that."
"The people from Wild Blue came to me and they were like, 'Look, our message is about spreading confidence in women and girls,' and they just said, 'I think our messages align,'" she says. "They do, because I'm about livin' original and being confident in the person that you are, so it was really not even about the clothes at first -- it was about the message."