It's been more than five years since the country darling first caught Blake Shelton's ear with her Pistol Annies-inspired blind audition on The Voice's second season.  "I heard this voice start to sing, and it was familiar, but it was also like something I'd never heard before," Shelton tells ET. "Instantly, she looked like a star standing there -- an unexplainable thing that she has about her that separates her from everybody else in the world."

Then just 17 years old, competing for Team Blake, RaeLynn was ultimately sent home by her coach during the competition's quarterfinals. And that's when the real work began.

"I went straight back to Nashville, started writing Monday through Friday, then got my butt in a van," the 22-year-old tells ET. "I went to every country radio station in the U.S., got ready in gas stations, lived off Starbucks and Chick-fil-A -- that's how it was. You have to do that groundwork."

In that time, she released a five-track EP with Big Machine Label Group (the longtime home of Taylor Swift) and cracked the Billboard Hot 100 with its lead single, "God Made Girls." She toured with both Shelton and his famous ex, Miranda Lambert, numerous times, and, by her estimate, wrote more than 200 songs. RaeLynn's voice is now stronger, her songwriting sharper, and her look more mature, trading flowers in her long blonde hair for tattoos, a cropped 'do and a marquise diamond on her left hand from husband Josh Davis, whom she wed in February 2016 and who, just last month, shipped off for basic training in the U.S. military.

Rae, as she's known to both friends and fans, likens it all to a college experience, culminating in something of a thesis: her debut album, WildHorse, out March 24.

"When you're a freshman to senior, you change so much in those four years and I've changed so much," she says of her post-Voice experience. "I'm so thankful that I've waited until now to put out my record, because I know I'm proud of this record."

The fact that The Voice has yet to launch a true superstar is not lost on RaeLynn (born Racheal Lynn Woodward) or her coach-turned-mentor, Shelton. As the show rolls through its 12th season in six years on NBC, both parties are making their case to change that narrative. 

"This is my thing," Rae says matter-of-factly. "No singing reality show is gonna make you a superstar. What makes you a superstar is what you do after that."

RaeLynn may not have chosen Adam Levine to be her coach, but he's proven to be a strong mentor all the same. She recalls his most powerful words of wisdom. 

"'Everybody who wants to be a singer now wants to have instant success and instant this and instant that,' he said, 'but it took me 10 years, it took Blake 10 years to get where we are today. They don't want to put that work in,'" she echoes. "So anybody who asks me, 'Should I do The Voice?' I'm like, 'Of course you should do The Voice! You should learn from that experience, you should get fans.' I said, 'But it doesn't stop when The Voice ends. You're not a superstar at that point. You have so much more work to do.'"