Britney Spears responds to Jamie Lynn's podcast interview

The feud between Britney Spears and her younger sister, Jamie Lynn Spears, continued Tuesday, with Britney responding to Jamie Lynn's latest comments on their relationship.

In a Tuesday afternoon post that was briefly deleted, Britney looked back on a particularly rough time — the period following her 2002 breakup with Justin Timberlake. She remembered marveling at the fact that Jamie Lynn, who turned 12 in April 2003, was enjoying chocolate milkshakes, watching TV and floating on a raft in the pool.

"I had worked my whole life and I didn't know how to be served by Mamma," Spears said, before questioning how her sister had her own show on Nickelodeon. (Zoey 101 lasted from 2005 to 2008.)

Britney went on to explain that she had been "scared" ahead of a People magazine cover shoot, because her mom, Lynne Spears, was on pain medication following her 2002 split with their father, Jamie. "I'm sorry Jamie Lynn," Britney wrote, "I wasn't strong enough to do what should have been done... slapped you and Mamma right across your f****** faces !!!!!"

By Wednesday, she had added on to her message:

She had also sent her sister a cease and desist letter.

Yahoo Entertainment reached out to reps for Jamie Lynn. Lynne Spears could not be reached for comment.

Britney's post appeared to be her reaction to her younger sister's appearances on the Call Her Daddy podcast, in which she explained that she had grown up thinking her feelings didn't matter, because it was all about Britney. The "Pretty Girls" singer responded to that, too, when she said that she has to ask herself, "Do I matter?" every day. "I didn't get to cry. I had to be strong. TOO STRONG."

In the same podcast, Jamie Lynn, who's been making the rounds for her new book, Things I Should Have Said: Family, Fame and Fighting It Out, said her sister had started to change around that time. She alleged that Britney had scared her by locking the two of them in a room with a knife.

But Jamie Lynn also defended her sister, who is roughly nine years older. "This was a brilliant young woman who was going through a hard time — and if she couldn't stand up herself, then somebody should have," Jamie Lynn said. "I wasn't an adult then. I couldn't… Somebody should have said, 'Stop the f****** presses. Give this girl a f****** minute.'"

She described having to deal with an "out of control" paparazzi a little later, when she was pregnant at 16 with her daughter, Maddie.

Britney blames Jamie Lynn and the rest of her family for the legal conservatorship she was under for almost 13 years, until a Los Angeles judge terminated it in November.

As Jamie Lynn discussed her book with ABC News last week, Britney wrote on social media that she had felt unwell during the interview. She was grateful because it made her "surrender to not caring."

"My family ruined my dreams 100 billion percent and try to make me look like the crazy one," Britney said then. "My family loves to pull me down and hurt me always so I am disgusted with them."

This story was originally published Jan. 18 at 5:41 p.m.