The Big Brother star died earlier this year aged 38.
According to a statement, the new documentary will show that “behind the bright and funny media persona, Nikki was a complex woman who bravely battled anorexia for over 30 years”.
It will feature interviews with her mother, as well as other members of her family and her friends.
Her mother, Sue Grahame, said: “Nikki was so much more than a reality TV contestant and I am looking forward to celebrating her short life in this documentary.”
She added it will “be tough, but Nikki was one special girl – kind and smart with the biggest heart”.
Executive producer Ollie Durrant said: “We are honoured to be making this important film with Nikki’s family and friends.
“She was an amazingly kind, caring person who despite her own struggles, worked tirelessly to raise awareness of anorexia and the exponential rise of mental health issues in society today.
“We hope this film is a fitting tribute to her legacy.”
Before finding fame on Big Brother, Nikki – then an aspiring actor – appeared as an extra in the BBC soap opera EastEnders and played a footballer’s wife in Sky One’s Dream Team.
She also appeared as a contestant on ITV dating show Blind Date and competed in the 2004 Miss Hertfordshire pageant.
After entering the Big Brother house dressed as a Playboy bunny, Nikki became known for her temper tantrums and Diary Room commentary, including her infamous “who is she?” remarks.
She eventually finished in fifth place, and landed her own E4 reality series, Princess Nikki, later penning two books about her experiences of living with a serious eating disorder.
Nikki returned to the house for Ultimate Big Brother in 2011, and took part in Channel 5’s Timebomb series four years later, before going on to appear on the Canadian version of Big Brother in 2016.
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