ET: Britney is 100% ready to address the court

[Slayer]

Britney Spears is "100 percent prepared" to address the Los Angeles court directly on Wednesday, a source tells ET.

In just a few hours, the 39-year-old singer is expected to speak out herself in the latest hearing for her ongoing conservatorship battle, which she's been under for 13 years. Britney will attend the hearing remotely, not in person, due to COVID-19 protocols.

"She's confident that she will have done everything in her power to regain her autonomy," ET's source says. "She is doing this with complete support from [boyfriend] Sam Asghari. He has stood by her throughout. She's been looking forward to this day for a very long time."

"Britney feels she is under a constant microscope, and she's been painted in the worst light," adds the source. "She feels as if she was never as out of control as so many people described her. She wants to impress on the courts that no one should have to endure losing control of almost every aspect of their life."

According to the source, Britney has been doing "really well" lately, and her boyfriend -- who is a health, fitness and nutrition expert -- is ensuring that she's been "making healthier lifestyle choices."

"They are very happy together," the source says, "and have put on a united front to ensure Britney gets some control of her life back."

Earlier on Wednesday, Sam took to Instagram Stories to share his support for his girlfriend on her big day. The fitness guru shared a photo of himself rocking a T-shirt with the words "Free Britney" painted in pink-and-purple writing. Sam also added a lion emoji at the top of the selfie, symbolizing the "lioness" nickname he often uses in his posts about Britney.

[Jordan Miller]

You got this, Britney! 

[GlitterSlayDExhaleHI]

I AGREE BRITNEY YOU HAVE IT IN YOU!

[TTrouble]

Do we know the schedule? Will we know anything today? 

[Jefferson Silva]

and boy SHE DELIVERED

[Britneylandia]

Yes she was. Proud of her!

FREE BRITNEY!!!