Britney Spears is apparently not too happy with sister Jamie Lynn Spears, who’s been making the media rounds in recent days to promote her new memoir Things I Should Have Said.

Previously, Spears issued a scorched-earth tweet blasting her younger sister for “lying” throughout the book, writing, “You’ve stooped to a whole new low. Please please stop with these crazy lies for Hollywood books. Now and only now I do know only a scum person would make up such things about someone.”

Meanwhile, Jamie Lynn recently appeared on the “Call Her Daddy” podcast, in which she spoke about her sister’s breakup with Justin Timberlake, among other things.

READ MORE: Britney Spears Responds To Jamie Lynn’s Interview: ‘You’ve Stooped To A Whole New Low’

Following the podcast’s release, the “Toxic” singer took to Instagram to share a message aimed at Jamie Lynn.

“In life a lot of people say “DO I MATTER ????” … try eating alone for 4 months morning ☀️ … noon 🕛 … and night 🌙 Jamie Lynn,” wrote Spears in the caption to the video, which features a sped-up version of Alanis Morrissette’s “Thank U” as a soundtrack.

“I asked myself every day ‘DOES ANYBODY CARE ??? WTF ??? DO I MATTER ???’ I would honestly be very interested to see your pretty face in the setting I was forced to be in and asking yourself ‘DO I MATTER ???'” Spears continued, still addressing her sister directly.

READ MORE: Jamie Lynn Spears Is In Tears As She Discusses Britney’s Breakdown, Claims Her Sister Offered To Buy Their Mom A House If She Divorced Their Dad

“I didn’t get to cry 😢 … I had to be strong … TOO STRONG 💪🏼 !!! So yes … YOU DO MATTER and don’t you ever think for one f**king second you don’t,” she added, concluding by addressing her familiar looking short plaid skirt paired with a white shirt. “Pssss this is my new …Baby One More Time outfit 😂💁🏼‍♀️ !!!!”