Britney Spears' sister has spoken publicly for the first time about the star's controversial conservatorship.

Britney told a court last week that the legal arrangement, which controls many aspects of her life, was "abusive" and she was "traumatised".

"I'm so proud of her for using her voice," Jamie Lynn Spears said in an Instagram story on Monday.

"If ending the conservatorship... or whatever the hell else she wants to do to be happy - I support that."

She added: "I am so proud of her for requesting new counsel like I told her to do many years ago.

"I'm not my family, I'm my own person. I'm speaking for myself."

Why hasn't Jamie Lynn spoken out before?

The actress, who stars in Netflix drama Sweet Magnolias, appeared to address criticism from Britney fans in her post.

Some who have backed the #FreeBritney campaign had questioned why Jamie Lynn had not been publicly supportive of her sister until now.

"The only reason I haven't [spoken out] before is because I felt like until my sister could speak for herself and say what she felt she needed to say publicly, it wasn't my place, and it wasn't the right thing to do," she explained.

"But now that she's very clearly spoken... I feel like I can follow her lead and say what I feel I need to say.

"I've made a very conscious choice in my life to only participate in her life as her sister," she added.

"Maybe I didn't support her the way the public would like me to, with a hashtag on a public platform. But I can assure you I have supported my sister long before there was a hashtag. And, I'll support her long after."

The term #FreeBritney dates back to 2009, according to a New York Times report, from a fan site that disagreed with the conservatorship agreement.

Jamie Lynn said that she had always been there for her older sister. "Since the day I was born, I've only loved, adored, and supported my sister," she continued.

"I don't care if she wants to run away to the rainforest and have a zillion babies in the middle of nowhere or if she wants to come back and dominate the world the way she has so many times before. I have nothing to gain or lose either way.

"I am only her sister who is only concerned about her happiness."

What happened in court last week?

In a 23-minute court appearance via phone, Britney told a court: "I just want my life back."

She told the judge she had been drugged, forced to perform against her will and prevented from having more children.

It was the first time the star had spoken publicly about the conservatorship, which began in 2008, when concerns over her mental health prompted her father Jamie to petition the court for legal authority over his daughter's life.

Mr Spears currently oversees the star's fortune, alongside a professional wealth management firm. A licensed professional conservator temporarily took over Britney's personal care in 2019. She has since opposed her father's return to the role.

After hearing her remarks in court, Mr Spears' lawyer issued a statement, saying: "He is sorry to see his daughter suffering and in so much pain. Mr Spears loves his daughter, and he misses her very much."