The sister of a toddler who went missing in Germany in 1981 described a woman who harassed their family on Facebook as "pure evil."
Troubled Donna Wright, 33, was handed a 12-week jail sentence suspended for 18 months after she admitted sending offensive messages to the family of Katrice Lee, in Hampshire.
Newton Aycliffe Magistrates' Court heard how the defendant had believed she was the missing girl and had made contact with the family.
When a DNA test proved she was not Katrice, Wright continued to send messages to a Facebook page set up to help the search for the girl, who would now also be 33.
Wright ignored a police warning to stop and was charged after sending 12 messages in a six-week period last autumn. She sent a further message in breach of a court-imposed bail condition.
Wright, who has a personality disorder and has been diagnosed as bi-polar, said in one distressing message her mother told her an uncle had "brought her a little girl because her family did not want her".
In another rambling email, she claimed: "I was brought over from Germany. Will you please help me look into this. It's a cover-up."
Most offensively she wrote in another: "You lost your daughter over a packet of crisps, you make me sick."
Katrice went missing from a shop near an Army base in Paderborn where her father Richard was serving with the King's Royal Hussars.
Katrice's mother Sharon, from Gosport in Hampshire, and father, from Hartlepool, believed their daughter was snatched and could still be alive.
Katrice's sister Natasha Lee, 39, wrote a victim statement which described Wright as "pure evil".
She said: "Every day is like a whopping nightmare for me.
"I am in an elite club that no-ones wants to be a member of.
"My sister has been missing for 31 years."
Ms Lee said Wright got in touch in December 2011 and initially she hoped she could be Katrice.
"However DNA proved she was not," the statement said.
"My parents have already suffered enough heart-ache and pain on a daily basis yet still they have to support me when I phone them crying.
"I am filled with dread every time I log on to Facebook in case I have a message from her.
"It is the first thing I think about in the morning and the last thing I think about at night.
"Devastated and heart-broken, I grew up not knowing where my sister is. This is even harder to bear because of Donna Wright.
"Valuable time and resources have been spent on this when they could have been spent looking for my sister."
Wright, 33, from Hillside Court, Spennymoor, County Durham, admitted the charge and in an unusual move was sentenced via a videolink while she sat in another court.
District Judge Martin Walker ordered her to pay £200 compensation each to Katrice's mother Sharon and sister out of her benefits.
He also imposed a "draconian" restraining order to prevent Wright from contacting the family, posting on Katrice's Facebook page, not to make public comments about the missing girl or her family, and not to change her own Facebook name or set up a new account.
He told the defendant: "It (the harassment) stops today for the sake of the family.
"It stops so you can focus on your own life rather than those of somebody else."
In a victim statement read out in court, Katrice's mother said the family initially had sympathy for Wright and they thought she would disappear after the DNA test.
"We believed once she received this information she would accept the facts and leave us alone. Sadly this was not to be the case.
"She continued to send messages under her own name or using aliases."
Her statement ended: "How much more do we have to take? How much more are we supposed to endure?"
Wright had a previous conviction for child cruelty and a caution for neglect, the court heard.
Leanne Galbraith, defending, said: "She apologises for the messages that have been sent, the words that have been said and she understands how hurtful those comments have been.
"She appreciates the impact on the family and she fully regrets her acts."
The solicitor added: "She has a genuine mental illness which is still being treated."
Judge Walker said the case was serious enough to warrant a jail sentence, which he suspended.
"The harm to the victims is gross," he said.
"It is extremely significant that after the DNA testing, this defendant must have known of the pain and grief that would have been suffered by the sister and mother of Katrice."
Outside court Mr Lee, who was supported by former comrades who were with him Germany when his daughter vanished, appreciated the concern showed by the judge.
"I still maintain Donna Wright did not get her just deserts," he said.
"I think a custodial sentence would have been great, however the judge had his work cut out.
"She is a very sad and sick individual."