Juliette Jackson is describing the song that made her feel human again. “It makes you feel like you’re not a fucking weirdo,” she says. “I got messages from people who get it. You find out that you’re not the only person who has Googled: ‘Can you die of sleep deprivation?’”

The track in question, Wide Eyes – released in July – was the first single from the Big Moon’s third album. Where the first two records from Jackson and her bandmates cocked a snook at bad men and the trials of twentysomething life (Jackson once described her aesthetic as “trying to seduce but stepping in dog poo”), the single found them in their rawest state yet. It’s the kind of slowly swelling, minor-key love song liable to make listeners’ bottom lips tremble, charting a bond that makes you ”want to dance” and “want to cry” at the same time.

That love, of course, is the new baby kind. Having got engaged (in true indie frontwoman style) on stage at Green Man festival in 2019, Jackson ticked off another milestone with the birth of her son last year. Channelling it into her output might seem challenging, given the often insouciant quality of the Big Moon’s music. Indeed, on the Mercury-nominated Love in the 4th Dimension – released in 2017 – Jackson and guitarist Soph Nathan, drummer Fern Ford and Celia Archer, the band’s bassist, made retro-flecked bangers on topics including a man trying to improve the taste of his semen, with more than a hint of Blur-ish sardonicism. On their 2020 follow up, the Top 20-bothering Walking Like We Do, stylish synthpop crept in, but levity still bubbled just below the surface (see: Take a Piece’s boyband-inspired video, or the quietly compelling Your Light). And yet, their new effort, Here Is Everything, sounds like exactly what it is: the same Big Moon but older, wiser and no longer sleeping on sofas on tour. “When you’re in your early 20s, you don’t really need personal space,” deadpans Ford.

Despite a marked reduction in side-eye, in person they retain the same fizzy energy, not only finishing one another’s sentences but often taking turns to form one full thought together, as though playing the childhood game where you write a sentence and fold over a piece of paper before passing it on. On the subject of folding birth-related trauma into music, it’s intriguing to see how they respond. “I should be allowed to [write songs] how I want, and have some distance from their subject matter,” says Archer. “I don’t need to let you assess my therapy.”

“That should be the whole point,” Nathan adds. Although it was Jackson who became a mother – and is the band’s lyricist – as everyone slips into first person over a coffee it feels like something of a shared experience.

Armchair psychology aside, one thing is certain: the band are very, very grateful to be back. The pandemic hit just after Walking Like We Do was released, and threw their plans – along with those of most of the music industry – off course. “We were gonna play the Royal Albert Hall?” asks Jackson, bemused, when reminded of plans that were junked overnight. “Every now and again someone says: ‘It was all coming for you that year’, and I hate it. It’s like, I actually didn’t realise all the things that might have happened until you just told me.” Other jobs were found (Archer worked on a farm, Ford and Nathan did delivery jobs and, er, Jackson covered a Woody Guthrie song with Courtney Love). Music lessons were taught online and further side hustles established, until the band could reunite.

They admit that they weren’t happy with their initial attempt at the new album. (“It was this lumpy thing from the past we weren’t dealing with,” says Jackson.) Luckily, Ford had constructed a studio in her flat during the pandemic, and the band self-produced their second run at the album, fuelled by an endless supply of tea and with the baby by their side. “Building it was a fucking headache,” says Ford of her home setup. “But I’m glad I did it.” Jackson bigs her bandmate up. “ That’s the stuff of dreams. That’s pretty major.” “Let us know if you need a carpenter … or a producer,” adds Nathan with a laugh.

The process was, says Jackson, “really special. The freedom to be able to make what we wanted to and have enough time to do it felt really good”.

The joys and despairs on the record are often as overt as Jackson’s Beyoncé-esque pregnancy shot on the album cover. On Wide Eyes, songwriter Jessica Winter helped her tease her love and exhaustion into stark verses and a singalong chorus, while 2 Lines is a tense, slacker-rock contemplation of the early phase of parenthood when “it’s too soon to shout, no fanfare yet” – and High and Low does indeed pose that million-dollar question about sleep deprivation. On Ladye Bay, the baby’s “bowling ball head” is a memorable punchline, but in other places the concept of motherhood is more oblique. “There are tracks that just sound like a pop song but which, to me, are wrapped in giant, fizzy, tangled strings of feelings that are so much more than that,” says Jackson. “Daydreaming is about breastfeeding – sitting there in a daze and just spending all day exhausted for months.” That’s all you do, day and night. I had such a bad experience breastfeeding – I couldn’t do it – and I was going through this period of loss. It was like a grief. With the song, I was trying to make it nice for myself and, I guess, recover a bit. Get some distance from it by writing a song that I wanted to dance to.”

Jackson is candid about how tough she has found things at times, and the dearth of help for new parents. “The official care you’re given isn’t enough,” she says. “You’re going through this massive hormonal crash, and it’s dark.” She quotes an interview Olivia Colman gave to the Guardian, where the actor said that she didn’t know anyone who hasn’t had “a little bit of postnatal depression”. “I really understood that,” she adds. “It’s really hard to stay on top of things. There needs to be more support.” The conversation continues for some time, with Jackson’s bandmates as passionate as her about making the music industry – and the world at large – more manageable for new parents.

You get the sense that, while challenging, the past few years have ultimately brought the band closer. While Wide Eyes is a song about their unofficial fifth member, the video is centred on the Big Moon coming back together – sans hand sanitiser – to perform an elaborately choreographed handshake masterminded by frequent collaborator Louis Bhose. “After all the hard work, it was perfect timing for something like that,” says Nathan.

Archer nods: “When you play together, you get oxytocin, that cuddle hormone. Gazing into each other’s faces, singing these really beautiful words and holding each other’s hands … it was really nice.”

Jackson continues the theme, as is the band’s habit. “You wouldn’t believe how many times we slapped each other’s hands,” she says with a laughs. “I had bruises down my arms from trying to get it right. It was great. I absolutely loved it.”

Here Is Everything is released on 14 October; The Big Moon tour the UK from Monday 19 to 28 September and 12 to 20 October.