Natasha Walker, 47, of Gosport is tomorrow marking the four decades since her younger sister Katrice Lee vanished on November 28, 1981.
But sick people pretending to be Katrice on Facebook continue to deluge Natasha with tormenting messages.
And despite one profile using photos of Katrice being flagged repeatedly with Facebook, the social media giant refused to take it down saying it had not gone against its policies.
Only after The News raised Natasha’s plight with Facebook was the profile removed from the platform.
Natasha said Facebook had acted in a ‘shameful’ way and it was wrong she could not get hold of anyone directly to raise her concerns.
Natasha, who was even subject to a temporary ban after challenging the profile, said: ‘I think it’s shameful.
‘Facebook has got big and there's no responsibility.
‘I've emailed them and said my sister has been missing for 40 years - this person is not my sister, and they still don't do anything about it.’
The profile had used Karice’s name and photos of the two-year-old previously published in the media.
Among the other tormenting messages Natasha receives was one from a woman who sent a message on Facebook.
She said: ‘Hello I am a friend of Antony but my Kindle went down and lost touch, so I think that he still has not let you know where her remains are?!’
The woman added: ‘Did your sister get murdered by Scott? Or I for the wrong family sorry x.’
When Natasha said she would be informing the police about the distress the woman is causing, she replied: ‘Send the police I will be waiting.’
Natasha told The News: ‘I thought I was going to throw up when I got that.
‘I was doing my mum's shopping that day and I had to go to my mum's and put on this big smiley face when inside that one comment about her remains was eating away in my head.’
Around 10 people have made contact with Natasha in this way over the years.
Natasha said she feels ‘sick’ when people contact her in this way because she knows what will happen next.
‘I can feel this underlying panic building up because they never just leave it at that,’ she said.
‘People say just ignore them. So I've ignored them. And I've woken up to 30 messages.’
Another person, claiming to be Katrice, sent a message that said: ‘Did your sister have a pigeon chest?’
The toll on Natasha is huge - and it’s down to her to report this to civilian police as her military police contact cannot do so.
This leaves her calling police on 101 - and explaining 40 years of history to a call handler from the beginning.
Natasha added: ‘I find that sometimes the more people that are contacting me thinking they're her, that might set my anxiety a little bit higher and the panic, but it's just trying to curb that.
‘And I think I'd be able to curb it better if I had more support from the military police, which I don't have.’
A Meta spokesman said: ‘We understand how upsetting this must’ve been for Katrice’s family.
‘Impersonating someone else is against our rules and we have disabled this profile.’