free britney
The singer also claimed that her “support system hurt me deeply” and that the conservatorship she's under “killed my dreams”.
"Please stop with the righteous approach when you’re so far from righteous it’s not even funny," she wrote on Instagram.
The singer was clearly in the mood to celebrate after being granted permission to choose her own legal representative.
"I want him removed and I want investigations. And I think that's it."
The singer is the latest star to speak out in support of Britney.
Britney recently said the conservatorship was "abusive" and said she wanted it to finally end after more than a decade.
"The best thing would be for their mom to be healthy and happy," Federline's attorney said of the former couple's two sons.
"I promise you she deserves all of the freedom possible to live her happiest life."
The singer's sister has insisted she's always been supportive of Britney, but preferred to do so privately.
Fellow singers Halsey and Tinashe, as well as Britney's old flame Justin Timberlake, have also spoken out.