Britney Spears has earned a $15 million deal for a “tell-all memoir” to publishers Simon & Schuster, which reportedly is “one of the biggest [deals] of all time, behind the Obamas.” After being freed from a 13-year conservatorship last year, which oversaw Spears’ finances, she has repeatedly spoken out about her experiences and even announced last week that she had been invited to discuss the conservatorship system with Congress.

While no official details about Spears’ book have been released, she had teased a memoir in recent months after her sister, actress Jamie Lynn Spears, had been promoting her own memoir. “I’m thinking of releasing a book next year,” Spears wrote on Instagram in October.

Spears went public with claims of lies within her sister’s memoir, “Things I Should Have Said,” which was released in January. The singer wrote on Instagram, “Congrats best seller…..The nerve of you to sell a book now and talk s–t but your (sic.) f–king lying…..I wish you would take a lie detector test so all these masses of people see you’re lying through your teeth about me !!!! I wish the almighty, Lord would could (sic.) come down and show this whole world that you’re lying and making money off of me !!!! You are scum, Jamie Lynn.”

Spears has been under the temporary conservatorship of her father since 2008, which did not allow her to get married or have another child – as she testified in November. She alleged that the conservatorship prevented her from being able to visit friends, go out with her boyfriend, and mandated the use of medication that made her “feel drunk.”

This legal battle led to the implementation of a conservatorship reform bill in the House of Representatives in July, known as the Freedom and Right to Emancipate from Exploitation Act (FREE Act).