The mother and father were each jailed for seven years for the crimes that even included giving their baby a morphine overdose days after her first birthday.
Miss Collins - who had met the family at a church lunch - gave evidence as a prosecution witness during the trial of the Nigerian parents, both 40, who cannot be named to protect their six children.
The couple claimed their kids were possessed by evil spirits - and alleged Miss Collins was involved in a witch hunt against them and wanted to 'steal' their children.
Five of the children were finally rescued after their eldest daughter threw an SOS note out of a window.
It read: "My mum is the worst mum ever because she can't cope with five of us, her broken hand and being pregnant. She always leaves me out so I always starve and I am forced to work.
"If I don't get enough house work done, I am beaten without mercy with the wooden end of a broom. I have scars all over me to prove it. I can't stay here. I would like a new mum."
It was found by a neighbour who called the police, and when officers attended the address they found the children living in messy conditions with 'dirty' and 'dishevelled' clothing.
Revealing scars, the eldest said her mother had hit her with a cable, a broom, and a hoover and her father had dangled her by her feet down the stairwell of the house, tied her hands behind her back and her legs together 'to get the devilish spirits out', prosecutor Emma Smith said.
Her sister, who was seven at the time, had a stick shaped bruise on her thigh and after a few months in care, she drew a series of pictures showing her dad beating her and her being left home alone, including a speech bubble saying, 'I'm hungry.'
But it wasn't until their the baby was given a morphine overdose over a year later that police reopened the case which led to their prosecution.
Sentencing them to seven years behind bars each, Judge James Patrick described it as 'shocking mistreatment' that they had tried to cover up with a 'web of deception'.
Judge Patrick said at Wood Green Crown Court: "No-one who sat through this trial could help but be moved by the fact that these intelligent, charming, fun, lovable children continue to love you despite what you put them through."