As Ariana Grande’s single Thank U, Next, topped the US singles chart, supergroup Pistol Annies reached No 1 on the US country chart with their third album, Interstate Gospel. It’s Miranda Lambert, Ashley Monroe and Angaleena Presley’s highest chart position yet, and shares DNA with Grande’s hit, approaching breakups with a sense of enlightenment. “I like the sound of that,” laughs Lambert. “We get over it quicker: females need a second to fall apart, have a mini nervous breakdown, a smidge of a pity party. Then you hunker down and make the best of it.”

Their recent single, Got My Name Changed Back, is a deadpan post-divorce romp celebrating the ordeal of reclaiming your maiden name, inspired by Lambert’s high-profile divorce from fellow country star Blake Shelton in 2015. The news barely made a ripple in the UK, but imagine the frenzy that would follow the Beckhams splitting and you’re halfway there. Lambert says “that song’s seed was planted at the DMV” when she had to amend her driving licence details after the divorce. “It’s huge to do that: change your name and change it back. Days and weeks of shit.” Monroe nods: that’s why she didn’t take her own husband’s name. “I don’t have an ex-husband,” she says, wincing. “Yet.”

The room is nervy. Maybe it’s the mention of old ghosts, or maybe it’s to be expected given that it’s the afternoon of the Country Music Association awards, where Lambert is the only woman to have won album of the year twice. The Annies are between fittings and rehearsals inside their management’s office on Nashville’s Music Row. As Presley strokes Monroe’s blonde extensions, Lambert perches on the edge of the sofa. The band haven’t celebrated their No 1. “I drank some milk,” Presley says, laughing and pointing at her pregnant belly; her second child is due in January.

When the Annies formed in 2011, Lambert already had multiple platinum albums and Grammy nominations. The biggest gig Presley had played was at Nashville’s Bluebird Cafe, with its capacity of 90 people. “None of us ever imagined we’d be in a girl band,” says Lambert. “I didn’t even have girls in my band on the road.” When Monroe played Presley’s music to Lambert they had a “drunken epiphany” and called her. Lambert and Presley had never spoken. “I thought they were high,” Presley recalls. “We were,” says Lambert. “But we meant it.”

Interstate Gospel is their first record together in five years. Since their last, Monroe married and had her first child. Presley – initially best known as a songwriter – started a solo career. Lambert’s relationship with Shelton provided the context for her sixth album – a double – the critically lauded The Weight of These Wings. The ideas kept coming: she texted her bandmates earlier this year while writing When I Was His Wife. They replied with a verse each. She can’t pinpoint how she knew it wasn’t solo material. “Jesus is our A&R guy,” she jests. “You can hear if it’s an Annies song.”

Monroe sees their strength in numbers as a way of sneaking in lines they wouldn’t have the courage to speak alone. “We sing harsher things; put a three-part harmony on it and it sounds kinda pretty,” she smirks. “You’re sassier with your two sisters by you,” adds Lambert.

Each songwriter takes personal risks on the album. Presley’s is Commissary, a song about the opioid crisis in her home state of Kentucky, sung from the perspective of a mother with a child in prison. She would be too afraid of people’s reactions to cut it alone. “I don’t know anybody who doesn’t know a person who’s died or gone to jail,” she sighs.

Pistol Annies shooting the video for Hush Hush in 2013. Photograph: Rick Diamond/Getty Images

For Monroe, Best Years of My Life was “too raw” to perform solo (“Well, he don’t love me but he ain’t gone yet / These are the best years of my life”). For Lambert, it was Masterpiece, a gorgeous song about maintaining appearances: “Baby, we were just a rodeo / Shining up our buckles for the show”. She bats away assumptions that it’s about her marriage. “It’s intimate but it could be about anything,” she insists. Monroe comes to her aid. “Masterpiece could be [about] the obvious but it could also be about the three of us. Everybody has a masterpiece that they don’t wanna take down.”

The ease of their writing partnership lies in their friendship and shared experiences. “It’s easier for us to invest in each other’s stories than if you’re on Music Row and some guy is [telling you what to do],” says Presley. Lambert nods. “We know everything about each other: darkness, best, all in between. It’s blood harmony.”

The country scene has always had matriarchs: from Dolly Parton and Loretta Lynn to Carrie Underwood and Shania Twain, but the industry’s conversation around feminism remains muted in the face of easily riled old-school gatekeepers. Lambert found herself in hot water the day before we meet when she told the Washington Post that it took a duet with Jason Aldean (Drowns the Whiskey) for her to top the country singles chart for the first time since 2014: “I had to sing with someone with a penis to get a No 1.”

Unbelievably, given that they’re three albums in, Got My Name Changed Back is the first Annies single to be playlisted on country radio. They must be delighted? “We’re not sure,” says Monroe. “It doesn’t mean it’s gonna play.” Industry publication Taste of Country reported that 2017 featured the lowest percentage of female voices on the radio – 10.4% – since 1994. “It’s a question mark above everyone’s head,” Presley says.

Their recent comeback shows were packed with women and men. “We sing from a woman’s point of view,” says Monroe. “But men know we’re singing about life.” Presley’s 11-year-old son listening to the group is as vital to her as it would be if she had a daughter. “I don’t want him to grow up thinking girls shake their booties at tailgates.” The women they sing about instead are complex and often damaged: wives and mothers looking at their lives and wondering where it all went wrong. “I’m broken all the way down to the bottom,” says Lambert. “I’ve screwed up my life. It’s strong to say that.”

• Interstate Gospel is out now on Sony.