Reality Winner's mother wrote an op-ed in the Intercept describing the "maddening" experience of watching her daughter" languish" in prison while major figures connected to the Trump-Russia investigation receive what she calls preferential treatment.

The now 27-year-old former NSA contractor was sentenced to five years and three months in prison back in August for leaking an intelligence report.

Billie Winner-Davis compared the justice system's handling of her daughter's case to the treatment of Michael Flynn, Paul Manafort, and Michael Cohen.

The mother of former NSA contractor Reality Winner is taking aim at some of the biggest names in the Trump-Russia investigation.

Billie Winner-Davis, whose now-27-year-old daughter was sentenced to five years and three months in prison for "removing classified material from a government facility and mailing it to a news outlet," published a scathing op-ed in the Intercept on Sunday.

"I am writing now because I am outraged: While my daughter languishes in prison, those actually responsible for threatening our election continue to get off easy," Winner-Davis wrote.

Winner was accused of leaking an intelligence report about Russia's efforts to influence the 2016 presidential election to the Intercept. Winner's sentence is, to date, the lengthiest ever given for such a federal crime. She was arrested June 3, 2017 and sentenced August 23, 2018.

Read more: How federal authorities identified Reality Leigh Winner as suspect in NSA leak

Winner-Davis singled out a number of figures implicated in the Trump-Russia investigation, writing that it was "maddening to watch my daughter in prison" while Paul Manafort, Michael Flynn, Rick Gates, George Papadopoulos, and Michael Cohen received "drastically different" treatment from the justice system.

She specifically blasted the fact that Manafort was permitted to remain outside of prison on bond before he was accused of witness tampering. She also singled Papadopoulos' 14-day prison sentence and highlighted indications that Flynn will not "receive a hefty sentence."

"I would have thought that someone of his rank and position within our government, someone who lied about the lucrative work he had done for one foreign government and contacts with another, would be held to a much higher standard than a 25-year-old veteran airman," Reality-Davis wrote.

Winner herself has spoken out from behind bars several times since her arrest. In August, she described watching the Russia investigation roll out from behind bars as "vindicating but also frustrating."

But in her op-ed, Winner-Davis said that her daughter's sentencing is proof of that the justice system protects the powerful.

"It sends the clear message that if you are poor and powerless in this system, you will be abused," Winner-Davis wrote. "I am outraged. I hope you are too."