Before the conservatorship ended in November, Britney Spears, 40, made it clear she was unhappy with members of her family – specifically her father, Jamie Spears, who at one point co-ran the conservatorship; as well as unnamed family members who the singer wrote vaguely online about not showing her support when she needed it.
"I've always been my sister's biggest supporter," Jamie Lynn Spears, 30, told ABC's Juju Chang during a conversation split between "Good Morning America" and "Nightline" for her first TV interview since the conservatorship ended. "So when she needed help, I set up ways to do so, went out of my way to make sure that she had the contacts she needed to possibly go ahead and end this conservatorship and just end this all for our family. If it's going to cause this much discord, why continue it?"
Britney Spears fired back at her younger sister in a series of tweets Thursday hours after the interview aired, writing Jamie Lynn "never had to work for anything" and "everything was always given to her."
"She was never around me much 15 years ago at that time.... so why are they even talking about that unless she wants to sell a book at my expense," Britney Spears added. "Hope your book does well, Jamie Lynn !!!!" USA TODAY has reached out to the pop star's lawyer for further comment.
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Jamie Lynn Spears is currently on a press tour promoting her upcoming memoir, "Things I Should Have Said," which promises to dive into stories from her childhood stardom, teen pregnancy, the accident that nearly killed her daughter, and, yes, her older sister.
"It was really important to me to first off, honor my voice," she added. "I have to do it or how else can I expect my daughters to stand up for themselves?"
In one passage shared during the interview, Jamie Lynn Spears writes about a fight with her sister during quarantine that was her "wake-up call" about who her family's priorities were with.
"Britney became enraged about something trivial," she wrote in the excerpt shared by ABC, and "came at me screaming and getting up in my face while I was holding (toddler) Ivey. Despite my best efforts, Britney continued on the attack, and (daughter) Maddie had to get in between us to protect her little sister until my parents could finally get Britney."
Jamie Lynn Spears recalled their parents, Jamie and Lynne Spears, telling her she "shouldn't get upset – that I can't upset Britney."
"You just saw me and my children get upset," she recalled replying. "When will I matter?"
Asked if she thought "speaking (her) truth" might harm her relationships, the younger Spears daughter said "nobody ever really considered me."
Chang mentioned a passage in the book that describes "an incident where Britney takes a knife, says she's scared and locks you and herself into a room." At other points, Jamie Lynn Spears describes her sister's behavior over the years as "erratic," "paranoid" and "spiraling." She said she chose to include those details because it felt important to note her own feelings at the time.
"I was a kid and in that moment I was scared. That was an experience I had," she said. "I also was really fearful to say anything because I didn't want to upset anybody, but I also was so upset that she didn't feel safe."
Jamie Lynn Spears said she "can't really speak to anyone else's state of mind" when asked how her sister's mental state is now – she's focusing on her own emotions.
"I don't think that's fair," she said. "But I'm allowed to say how I felt… because that matters. It matters that I was in pain."
A California judge ruled Nov. 12 that Britney Spears was officially free of her conservatorship, which had been put into place nearly 14 years prior after she suffered a public breakdown that played out before the paparazzi. Jamie Lynn Spears said she was "happy" after the conservatorship ended.
"If that's what makes Britney and everyone else happy, that's what should happen and that's all it is," she said. "It has so very little to actually do with me, except for the well-being of my family members."
"Everyone has a voice and it should be heard," Jamie Lynn Spears added, noting that she at one point spoke to her sister's "previous legal team" but it "didn't end well."
"I did take the steps to help, but how many times can I take the steps?" she added. "You know, she has to walk through the door."
Despite a rift in the family dynamic, Jamie Lynn Spears says "that love is still there" for her sister, "100%."
"I love my sister," she said. "I've only ever loved and supported her and done what's right by her, and she knows that, so I don't know why we're in this position right now."
Contributing: Charles Trepany and Maria Puente