Panusaya was detained on charges of sedition and illegal gathering among others for her alleged role in the anti-establishment rally on September 19 last year.
Her mother had on Thursday morning presented a guarantee of Bt200,000 to seek her release for medical treatment, after Rung reportedly became weaker following several days of fasting.
Panusaya reportedly started skipping dinner since March 30 after she was been denied bail.
The court has granted her temporary release on the condition that she must not repeat the offences for which she has been charged, she must not participate in any activities that could cause disorder in society, she must not leave the country without the court's permission, and she must be present along with her lawyer every time the court summons her.
Panusaya was seen leaving the prison in a personal car at 5pm, without speaking to the media. Her family reportedly said that they would take her to a hospital for treatment immediately.