Another furious Instagram post from Britney Spears might soon be on its way. Tensions have been rising between the singer and her younger sister, Jamie Lynn Spears, who just gave another tell-all interview in the run-up to her new memoir, Things I Should Have Said.

The first installment of the Sweet Magnolias actress’ interview with podcaster Alex Cooper dropped Monday night, and its follow-up will be released Tuesday night on Spotify. Part one explores Jamie Lynn’s upbringing as the “oops baby” within the Spears clan, and how the tabloid frenzy surrounding their family made life unbearable for pretty much everyone involved. Jamie Lynn also detailed a widely discussed anecdote from her book in which Britney supposedly locked them in a room with a knife, as well as the ways their family and teams kept the sisters isolated from each other.

Britney Spears has recently spoken out against her sister for publishing a book at her “expense” in an increasingly intense public feud. As a source told Page Six, “Now that she’s free, Britney wanted to share everything that she’s been through when she was ready, but Jamie Lynn beat her to the punch.” TMZ reports that Jamie Lynn has axed her upcoming book tour after asking her sister to bring their “embarrassing” public exchanges to an end. (Britney, meanwhile, appears to be softening her tone as well; she ended her most recent post directed at her sister with the words, “Just know I love you.”)

During her interview on Cooper’s podcast, Call Her Daddy, Jamie Lynn recalled growing up “insulated” by her older siblings, Britney and Bryan, whom she believes helped shield her from some of their father’s destructive behavior. Jamie Spears is now sober, Jamie Lynn said, but his alcoholism was disruptive during her upbringing and contributed to what she described as unhealthy and skewed parent-child dynamics—especially once she and Britney began to help support their family financially.

“Of course [I felt] like her little doll,” Jamie Lynn said of Britney, “but at the same time I felt like she was my protector, I guess… and I admired her, too. I loved her, everything about her.”

Britney became a household name when Jamie Lynn was in first grade. The actress remembers hearing her older sister’s song on the radio while she and her friends played on a trampoline. Realizing that her sister was a “real” singer was exciting for Jamie Lynn, who at one point during her interview decried fans’ claims on social media that she was jealous of her sister’s success. “I got to experience watching a woman take over the fucking world; how can I be jealous of that?” she said. “How can you have anything but complete admiration for it?”

But the fame was also terrifying to process at times, Jamie Lynn said—especially because they were living in a less-than-secure house in Kentwood, Louisiana, where she recalled her mother making lunch for obsessive fans who came by.

When Cooper asked Jamie Lynn about a passage in her book that claims she began noticing “destructive behaviors similar to our father’s” in her older sister, she appeared to soften. “She was wanting to escape us a little bit more… which was normal,” Jamie Lynn said, adding that the adults around her wrote it all off as a “party stage.”

Then came the knife anecdote, which Cooper quoted directly from the book: “Britney said to me, ‘Baby I’m scared.’ And she took a large knife from the kitchen, pulled me along to my room and locked us both inside. She put the knife in the bedside table drawer and simply repeated, ‘I’m scared.’ … I knew something was wrong and I was powerless to do something about it.”

Jamie Lynn said the incident occurred soon after Britney’s whirlwind marriage to her longtime friend Jason Alexander in Las Vegas. “I never felt like she was going to harm me or anything,” she said. “It just felt weird. And I didn’t understand it.” After telling her parents what happened, Jamie Lynn said, her sister’s team “asked me to come in there and tell this therapist about it and I did. And then I never heard anything else about it.”

“I think this was a brilliant young woman who was going through a hard time,” Jamie Lynn added, “and if she couldn’t stand up for herself then somebody should have. I wasn’t an adult then, I couldn’t. Somebody should have said, ‘Stop the fucking presses. Give this girl a fucking minute.’”

Jamie Lynn also detailed her tumultuous relationship with her mother, Lynne, who once beat her on the shoulders with a purse that held a camera inside.

“I’m still in real time sharing these things,” she said. “And they’re not easy for me… It’s hurtful for me to work through this because sometimes I think I don’t say it right or I don’t know how to say it because it’s still painful and I’m still processing it. But one of the main steps is actually saying it out loud, I guess… At the end of the day I have to use my voice or else I’m not gonna teach my children to do it.”

The main thrust of Jamie Lynn’s interview—the first portion, anyway—centers on the toxic tabloid environment she and her sister faced, and the lack of adult support with which they faced it. In particular, she describes her frustration with their mother, whom she wished would have stood up for her more—both against their father and, later, against other adults who made Jamie Lynn feel it was her responsibility to help protect her sister’s narrative without granting her any control of her own.

“Imagine a big ship and I’m just the little dingy riding in the wakes trying to survive… That was my life, just survive this moment,” she said. She recalled finding out at a friend’s house that Britney had shaved her head in 2007, which Jamie Lynn faced alone as her parents were out of town to help her sister. She dreaded going to school the next day, and while she knows she must have spoken with her parents about the incident at some point, “I don’t even remember talking to them about it… It was all coming apart and I was like, ‘I gotta sit here and grin and bear it like I was taught to… I wish I’d had somebody to talk to about it, you know?”

Jamie Lynn also hit back at the idea that she rode her sister’s coattails to build her own acting career: “Why can’t two sisters exist in their own right? We never compared each other; the world did. We never had that dynamic or that issue. My sister is going to always, to me, be the most badass performer who ever walked this earth. Nothing’s gonna change that. The problem was I couldn’t be responsible for everything that happened around her and also be authentic to myself. And I wasn’t allowed to be.”

Although Jamie Lynn kept her composure for most of the interview, she began to cry as she told Cooper, “My whole life I felt like I didn’t matter. So I just wish that mattered.”

Jamie Lynn said the moment she chose to seize her own agency was when she got pregnant at 16 and, against her team’s alleged wishes, declined to get an abortion. “My soul was telling me I wanted my baby.” She told Cooper that she sold her birth announcement to OK! magazine in an attempt to control the narrative, but predictably, the tabloids savaged her anyway.

As she discussed her pregnancy and the controlling, isolating tactics various adults around her began to exhibit, Jamie Lynn also hinted at another theme of her memoir: that she, too, has been forced to explore legal action against her family.

To this day, Jamie Lynn can’t remember whose idea it was for her and Lynne to go stay in a remote cabin somewhere in the Northeast once the news of her pregnancy broke—but she says she does remember exactly how much it cost her. She was not allowed to tell her own sister that she was pregnant; instead, Britney found out from tabloids. “They said it was too risky to tell Britney about the baby,” she said, although the reasoning behind that notion remains hazy.

Jamie Lynn recalled becoming increasingly frustrated with her parents after the news of her pregnancy broke, especially as they attempted to control when she could see the father of her child. She had to tell her mother where she was at all times, and the adults in her orbit seemed to want Jamie Lynn to live with her mother and raise her baby there—an idea she vehemently opposed.

“It became the point where like, ‘OK, I’m pregnant. Everyone knows. I thought the reason you were keeping me so locked away like a princess was because of the story… so why am I still being monitored like this?’” Jamie Lynn said. “… It’s almost like maybe if they made it not exist enough it didn’t exist.”

Eventually, she connected with a lawyer and began exploring her options—which sparked her plea for emancipation. The move made news at the time, and Jamie Lynn said she’d been lying to her parents and saying she was attending doctor’s appointments while she clandestinely met with a lawyer. Ultimately, the family reached a compromise in which Jamie Lynn would maintain financial and personal autonomy and her parents could step in if things began to go off the rails. Then, she said, “I just loaded up all my shit and left.”

From the previews included in part one of Jamie Lynn’s interview, it appears part two will focus on the subject listeners are probably most eager to hear about: the details of Britney’s conservatorship and how much her sister knew about it. Jamie Lynn denies any involvement in the conservatorship, and when asked to name the most hurtful accusation she’s faced on social media, she replied, “That I didn’t do anything to try to help my sister. I very much did many things.”