Just as the local elementary-school Barton Hills Choir finished their half-hour performance on the Austin Kiddie Limits Stage at ACL Fest, 13-year-old Grace VanderWaal began an hourlong show on the adjacent HomeAway Stage. If there were any doubt, those back-to-back sets affirmed that, yes indeed, the kids are all right.

VanderWaal will release her first album, appropriately titled “Just the Beginning,” next month — and what a beginning it is. VanderWaal created a buzz around the grounds after her performance last weekend, so it was no surprise to find quite a sizable crowd for an early-afternoon set greeting her for weekend two. Performing beautiful pop songs that highlighted her soaring voice and occasional ukulele playing, VanderWaal charmed a crowd that included plenty of die-hard mega-fans up front and a lot of curiosity-seekers further back.

Leading off with “Moonlight,” an early single from her new album, and proceeding to favorites from her 2016 EP such as “Light the Sky” and “Gossip Girl,” VanderWaal simultaneously impressed the crowd with her natural talent and charmed them with her youthful wonder. “I know a lot of you don’t know who I am, and that’s totally fine,” she said midway through the set. “I know some of you might,” she added, to the uproarious cheers of fans who got to know her from her appearance on the TV show “America’s Got Talent” (when she was still a pre-teen).

PHOTOS: Grace VanderWaal at ACL Fest

VanderWaal’s potential may be boundless, but it’s worth noting that she’s still learning, as any 13-year-old would be. A well-meaning introduction to “Talk Good” went on a little too long, and on the set-closing “I Don’t Know My Name” (which helped launch her career), she relied a little too much on sing-along the superfans singing up-front, to the detriment of folks further back who might have liked to hear her own voice more.

Still, part of VanderWaal’s appeal is that she knows she’s still finding her way. On “Better Life,” a wonderful ballad from the upcoming album, she fessed up midway through to getting a verse out of order, and apologized to a bandmate: “I’m sorry I sang through your guitar part!” Her three-piece band supported her admirably throughout on guitar, drums and keyboards, and she made sure to give them full credit, as well as her sound crew.

You’ve heard the line before about singers with such great voices that they could sing the phone book and it would be worthwhile. For VanderWaal, the parallel is perhaps “Happy Birthday.” It’s almost impossible to make that chestnut sound anything more than an obligation to get through quickly, so when she accepted the request from three fans in the crowd, it seemed perhaps unwise. But VanderWaal made the dedication to Kevin, Emma and Mary sound first musically magnificent and then uproariously fun.

VanderWaal seemed genuinely impressed with the city and the festival on her first visit here. “I want to come back to Austin every day. You live in the coolest place,” she beamed near the end of the set, admitting that she had no idea what to expect before she arrived. “I just thought, like, Ohio. But it’s pretty awesome!”

Watch: Grace VanderWaal’s birthday wish to a special fan

What comes next for VanderWaal? “I hope she can find a safe, true-to-herself path through early stardom. A lot of pressure!” a fan wrote on Twitter in response to a video clip from Saturday’s performance. There’s so much talent here that it does indeed feel like the sky’s the limit. Are we looking at the dawn of another pop start like Taylor Swift? Or perhaps more of a Grammy-winning Americana sensation like Wimberley-raised Sarah Jarosz. Wherever she goes from here, ACL Fest was fortunate to have her aboard this weekend.

13 years old and winning #ACLFest: @GraceVanderWaal . pic.twitter.com/3wgRVYmtJ4

— Peter Blackstock (@Blackstock360) October 14, 2017