Britney's medical records are sealed and she has never disclosed any mental health issues and so the "hope is that she can eventually get out of the conservatorship".
Although Britney hit out at the treatment she's received from her conservators, which also includes her father, Jamie Spears, the insider insisted those overseeing her affairs have been investigated by the court.
The source said: "Under California law, all conservators have to be investigated secretly by the court.
"Progress has to be reported. Conservators are all closely monitored to assure nothing shady is happening."
Jamie is in charge of Britney's financial affairs and is very much involved in her day-to-day life because of the nature of the decisions he has to make.
The insider explained: "Even though Jamie is in charge of her finances, he still has to approve everything because everything is related to finances at the end of the day.
"If she wants to go to Hawaii, he has to approve that, because it costs money. If she wants to take her friends to dinner, he has to approve that, because it costs money. Jamie has the right to say no to certain things."
When she spoke to the court last week, the Lucky singer – who has sons Sean Preston, 15, and 14-year-old Jayden with ex-husband Kevin Federline – admitted she hadn't expected anyone to believe how her life has been under the conservatorship.
She said: "I've never said it openly - I never thought anyone would believe me.
"I'm not lying. I just want my life back. It's been 13 years, and it's been enough. I want to be able to be heard. I've kept this in for so long - it's not good for my heart.
"I've been so angry and I cry every day. For my sanity ... I need to get it off my heart. The anger, all of it.
"The main reason why I'm here today is I want to end the conservatorship without being evaluated."
