The pop superstar, 39, shared an image to Instagram of an artsy underwater scene where one woman swims down to check on another as she lies on her back seemingly helpless.
"This picture is everything to me !!! It makes me want to cry ... she’s saving her divine feminine sister !!!!" she wrote.
The "Toxic" singer, 39, referenced her controversial 13-year conservatorship, under dad Jamie's control, saying nobody helped her.
"I suggest if you have a friend that’s been in a house that feels really small for four months … no car … no phone … no door for privacy and they have to work around 10 hours a day 7 days a week and give tons of blood weekly with never a day off … I strongly suggest you go pick up your friend and get them the hell outta there !!!!!" she wrote, referencing some of the allegations of conservatorship abuse she made in court in June.
She took aim at the Spears family — which includes mom Lynne, brother Bryan and sister Jamie Lynn — specifically.
"If you're like my family who says things like 'sorry, you're in a conservatorship' … probably thinking you're different so they can f**k with you !!!!" she wrote.
Britney ended by saying she's thankful she "found an amazing attorney Mathew Rosengart who has helped change my life," after stepping into the role in mid-July and having Jamie suspended on Sept. 29.
The next hearing in the case is Nov. 12 with Rosengart saying he wants the entire conservatorship ended by the end of the fall.
When Britney spoke out in court in June, she alleged she was forced to work, take medication and enter a mental health treatment facility against her will. While Jamie served as conservator of her estate, profiting handsomely off it, she suggested they played a role in keeping her in it.
"I want to sue my family to be totally honest with you," she said.
Her mother began stepping up her involvement in the conservatorship case, as an interested party, over the last year. Lynne called for her ex-husband Jamie to be removed. Meanwhile, Britney has previously called out sister Jamie Lynn online for seemingly not supporting her.
But Britney's has sunnier days ahead. She and her Sam Asghari, a model and trainer, were engaged last month and are planning their wedding. Last week, they celebrated her conservatorship victory on vacation at the Brando Resort in French Polynesia. Typically, the pair needed approval from Jamie to travel and on any spending while they were away.
"She is very hopeful now that her dad is out," a source told People magazine for its cover story. She already feels "more freedom" and was "ecstatic" to be able to "pick her own vacation spot," noting that's "a big deal... Britney thinks everything will be totally different with Jamie out of her life."
As for whether Britney will return to the stage, that remains to be seen. She's said, via her previous lawyer, she wouldn't perform again until her dad was removed.
"It seems she's just not ready," the source said, though noted, Asghari "has encouraged her to think about performing again." She wants the conservatorship to end, but she doesn't seem to have a plan beyond this."
She is planning for a "small wedding as soon as possible" and the mom of two wants "more kids." Her vision is a "simple life" — Asghari, her kids, workouts, gardening and making art. "She just wants to start fresh."
Plans are already underway for what happens if the judge ends the conservatorship.
"The goal is to have the conservatorship terminated but continue protecting Britney and her finances," another source told People, noting her $60 million fortune will likely be put into a trust with professional managers.