Britney Spears has hit out at Jamie Lynn Spears in another furious social media post.After the Sweet Magnolias actress recalled how she was "so sad" that her older sister and Justin Timberlake had broken up in 2002 during an appearance on the Call Her Daddy podcast on Monday, Britney took to Instagram to claim that Jamie Lynn wasn't supportive of her at the time, and that her sibling was actually sat at home watching TV and being "served by Mamma". While the Stronger hitmaker later deleted the post, she re-uploaded it on Wednesday afternoon, and added more detail to her argument. "I'm sorry Jamie Lynn, I wasn't strong enough to do what I should have done… slapped you and Mamma right across your f**king faces!!!!! And WHY do I say that???? You selfish little brat!!!" she fired. "Saying how weird and dumb it was that I bought a house for Mamma!!!! She was so proud and you told that interview girl that it was just weird." Britney went on to note she was "shocked out of my mind" by the way Jamie Lynn allegedly spoke to their mother when she was at home, and claimed her sister and her friends dyed their hair to resemble the pop star's then-rival, Christina Aguilera. "When I came home you and your little friends all thought I wasn't cool … You felt bad for me in the breakup … HELL NO you didn't!!! You are your friends all dyed your hair like Christina Aguilera and you no longer would play with me anymore!!! I NEVER shut you out ever," the 40-year-old continued. "I get it, you were 12 but you were f**king hateful to Mamma being cool with your stupid dark hair. You can paint it however you like but dear child… YOU shut me out when I needed you the most!!! Writing in your book saying I wasn't like your mom anymore… No, you hurt me (sic)." Jamie Lynn has not yet responded to Britney's allegations. On Tuesday, Britney's lawyer Mathew Rosengart sent the 30-year-old a cease and desist letter asking her to stop talking about the Toxic hitmaker "derogatorily" while on her press tour for her new book, Things I Should Have Said.