Gypsy Rose Blanchard set to be paroled years after persuading ...

Gypsy Rose Blanchard, the Missouri woman who persuaded an online boyfriend to kill her mother after she had forced her to pretend for years she was suffering from leukaemia, muscular dystrophy and other serious illnesses, is set to be paroled on Thursday.

The case sparked national tabloid interest after reports emerged that Gypsy Blanchard's mother, Clauddine "Dee Dee" Blanchard, who was slain in 2015, had essentially kept her daughter prisoner, forcing her to use a wheelchair and feeding tube.

It turned out that Gypsy Blanchard, now 32, was perfectly healthy and not developmentally delayed as her friends had always believed.

Her mother had Munchausen syndrome by proxy, a psychological disorder in which parents or caregivers seek sympathy through the exaggerated or made-up illnesses of their children, her trial attorney, Michael Stanfield, said.

Through the ruse, the mother and daughter met country star Miranda Lambert and received charitable donations, a trip to Disney World and even a home from Habitat for Humanity.

Mr Stanfield said Dee Dee Blanchard was able to dupe doctors by telling them her daughter's medical records had been lost in Hurricane Katrina.

If they asked too many questions, she just found a new physician, shaving the girl's head to back up her story.

Among the unnecessary procedures Gypsy Blanchard underwent was the removal of her salivary glands. Her mother convinced doctors it was necessary by using topical anaesthetic to cause drooling.

Gypsy Blanchard, who had little schooling or contact with anyone but her mother, also was misled, especially when she was younger, Mr Stanfield said.

"The doctors seem to confirm everything that you're being told. The outside world is telling you that your mother is a wonderful, loving, caring person. What other idea can you have?" he said.

But then the abuse became more physical, Mr Stanfield said.

Gypsy testified that her mother beat her and chained her to a bed. Slowly, Gypsy also was beginning to understand that she wasn't as sick as her mother said.

"I wanted to be free of her hold on me," Gypsy testified at the 2018 trial of her former boyfriend, Nicholas Godejohn of Big Bend, Wisconsin, who is serving a life sentence in the killing.

She went on to add: "I talked him into it."

When she took the stand at his trial, prosecutors already had cut her a deal because of the abuse she had endured.

In exchange for pleading guilty in 2016 to second-degree murder, she was sentenced to 10 years in prison.

The first-degree murder charge she initially faced would have meant a life term.

"Nick was so in love with her and so obsessed with her that he would do anything," Godejohn's trial attorney Dewayne Perry argued in court, saying his client has autism and was manipulated.

Prosecutors, however, argued that he was motivated by sex and a desire to be with Gypsy Blanchard, whom he met on a Christian dating website.

According to the probable cause statement, Gypsy Blanchard supplied the knife and hid in a bathroom while Godejohn repeatedly stabbed her mother. The two ultimately made their way by bus to Wisconsin, where they were arrested. She has been incarcerated since then at a state women's prison.

"Things are not always as they appear," said Greene County Sheriff Jim Arnott as the strange revelations began to emerge.

Even Gypsy's age was a lie. Her mother had said she was younger to make it easier to perpetuate the fraud, and got away with it because Gypsy was so small: 150 centimetres tall.

Law enforcement was initially so confused that the original court documents listed three different ages for her, with the youngest being 19. She was 23.

Greene County prosecutor Dan Patterson described it as "one of the most extraordinary and unusual cases we have seen."

Mr Stanfield recalled that the first time he met Gypsy, she got out of breath walking the 69 metres from the elevator to the room where he talked to her. He described her as malnourished and physically frail.

"Prison is generally not a place where you become happy and healthy. And I say that because, to me, that's kind of the evidence to the rest of the world as to just how bad what Gypsy was going through really was."

Gypsy Blanchard later said it wasn't until her arrest that she realised how healthy she was. But it took time. Eventually, she got married while behind bars to Ryan Scott Anderson, now 37, of Saint Charles, Louisiana.

The bizarre case was the subject of the 2017 HBO documentary Mommy Dead and Dearest, the 2019 Hulu miniseries The Act and an upcoming Lifetime docuseries The Prison Confession of Gypsy Rose Blanchard.

Daytime television psychologist Dr Phil McGraw interviewed her from prison. The novel Darling Rose Gold draws upon the story for its premise and Blanchard's own account, Released: Conversations on the Eve of Freedom is set for publication next month.

Amid the media storm, corrections department spokeswoman Karen Pojmann said no in-person coverage of her release on Thursday would be allowed "in the interest of protecting safety, security and privacy."

AP/ABC