From Dakota Johnson to Ben Stiller, nepo babies can be flat-out awesome.

Friday at Austin City Limits Music Festival, 21-year-old Sienna Spiro, fresh off a Best New Artist Moonman at the MTV VMAs, poured out her soul for 45 minutes. The jazzy British singer is the daughter of jeweler Glenn Spiro, whose clients include Beyoncé and Gwyneth Paltrow. He’s sold stones for $3.4 million apiece at Sotheby’s.

Does that make his daughter beneficiary of nepotism? Look around: The music industry is ripe with connected and wealthy artists who had significant creative support growing up. Here at Zilker Park, Stella Lefty’s dad is a tech billionaire. Steve Aoki’s dad is the founder of Benihana. Lorde’s mom is an award-winning poet. Charli XCX’s dad is a talent agent. The band Geese met at the Brooklyn Friends School, where tuition is more than $65,000 a year. 

But something funny happened during Spiro’s mid-afternoon ACL Fest set on the Miller Lite stage: Thousands of teens cried along to her relatable songwriting. This reporter got a little teary, too, which is the involuntary reaction you always want at a show.

You’ve seen these exhausting jazz singers from England, from Olivia Dean to Raye. Their Starbucks pop is textbook easy, flat listening. Their bands wear suits and pantomime over backing tracks. It’s jazz club music for people who go to jazz clubs — and talk. 

Sienna Spiro, however, is a storyteller. She’s more like Adele. Her heart is on her sleeve. Her lyrics sting. She cops to being “too sentimental” on breakup ballads. 

“I’m gonna bring the mood down quite drastically,” she’d admit pre-song, rocking a polka-dotted dress. Songs like “He’s Not My Baby I’m His” are cautionary tales about power dynamics.

She sang with raspy purpose in soaring, human fashion. And when she covered Otis Redding’s 1968 standard “Hard To Handle,” she introduced her backing band — and they did something you never see at ACL nowadays. They didn’t just wave to the dang audience. They each flexed their technical prowess with solos.

Here a sea of distraught and dehydrated teens cried, sang while recording on their phones and screamed with British Invasion fervor. It was empowering. They’ll spin her records forever.

“I know I’m temporary,” Spiro belts on “The Visitor.” “It’s in my nature to be cynical.” It’s cutting work that afforded Spiro the luxury of letting her fans carry the tune.

Would Spiro be at ACL without her family’s estate? Not yet. But given the opportunity to step into the ring, she landed every body blow.

“I’m about to faint,” Spiro told onlookers before closing with her megahit, “Great Expectations.” Same.