After her early days as “a hustler … playing four-hour sets in seafood restaurants and s–t,” Brandi Carlile was more than ready for her Grammy moment on music’s biggest night in February.

“I had just won three Grammys, and I was getting the opportunity to do exactly what I know how to do, which is rock and roll — just playing guitar to live drums and screaming my head off,” says Carlile of performing “The Joke.” “I was just determined to experience it in real time and not in retrospect because of nerves. I just had fun.”

No doubt, after delivering one of the show’s best performances, the rootsy singer-songwriter is still living the Grammy dream as she gets ready to headline Madison Square Garden for the first time on Saturday.

“I’m still trying to catch up to what happened emotionally — it’s kind of changed my whole life,” says Carlile, 38, of a night that included improbably high-fiving Post Malone backstage. “I’ve never been one of those artists that can act impervious or like I don’t care. I mean, I cared a lot … It’s opened the doors to so many collaborations I’ve always wanted to do. It’s opened the door to so much philanthropy and activism I’ve always wanted to be around. And it’s just made life really exciting for me — and for my wife and kids too.”

Indeed, Carlile’s three Grammys — for Best Americana Album (2018’s “By the Way, I Forgive You”), Best American Roots Performance (“The Joke”) and Best American Roots Song (“The Joke”) — are displayed “loud and proud” for all the family to see on the fireplace mantle in the living room of their Seattle home. “My oldest girl is obsessed with them — she thinks that they’re real gold,” she says of daughter Evangeline, 5.

Carlile and her wife Catherine — who also have an 18-month-old daughter, Elijah — got hitched seven years ago in Boston. Being an out artist hasn’t hurt her career in any big way, she says.

“I have a lot of people to thank for that, [people] that did find it a challenge,” says Carlile, who earlier this week won Artist of the Year at the Americana Music Association Honors Awards. “There was some residual connotation attached to being an androgynous lesbian artist … But as I’ve gotten older, I’ve seen that dissipate and dissolve. I’ve seen artists like Courtney Barnett come on the scene with a ferocious mullet and just dominate, and nobody even thinks anything other than ‘How cool is Courtney Barnett?’ And that makes me so proud. And it makes me so grateful to, like, the Indigo Girls.”

Carlile has teamed up with three other female artists — Maren Morris, Amanda Shires and Natalie Hemby — to form the new country music supergroup the Highwomen. The name of the quartet — which released its self-titled debut album last week — is, of course, a nod to the Highwaymen, featuring Johnny Cash, Willie Nelson, Waylon Jennings and Kris Kristofferson.

“All of us, with the exception of Maren Morris, are mothers of young daughters,” says Carlile. “And we all noticed in really profound ways that women are not given a platform in music right now. We’ve noticed it on the touring front, on the executive level, at radio stations. And we want young girls — and women of any age — to have access to women telling the story of the other half of the human race. And I think that the genre that could really use the help in that respect is country music.”

To also stand up for women, Carlile is spearheading her second Girls Just Wanna Weekend, an all-female-fronted festival that will take place at the Hard Rock Hotel in Riviera Maya, Mexico, early next year. “It sold out immediately both years,” she says. “It might send the promoters back home a message that women can sell tickets to festivals. I’m gonna keep trying to do it, and I wanna bring it to the US as well.”

For now, though, the big gig on her mind is the Garden on Saturday. “I’m a road dog — I’ve been dedicated to the road for 20 years,” says Carlile. “So I am so proud to be headlining Madison Square Garden. It’s unfathomable, but I’m just gonna own it. I’m saving everything for it.”