Star was punched and stamped on by her mother's lover Savannah Brockhill, 28, in Keighley, West Yorkshire, on September 22.
The fatal attack came after months of maltreatment and psychological torment that went unchecked by social workers despite five complaints.
Star's mother, Frankie Smith, 20, was exonerated of murder but convicted of causing or enabling her death.
Arthur Labinjo-Hughes, 6, was recently tortured, poisoned, and murdered by his stepmother Emma Tustin.
Last Monday, Secretary of State Nadhim Zahawi ordered a national review into Arthur's death.
He added: ‘We must protect youngsters from these terrible crimes and teach them lessons.'
Concerned family contacted social services five times about Star's bruising, and police visited the residence.
Brockhill and Smith persuaded the social workers that the toddler's marks were unintentional or that the complaints were malicious.
David Fawcett, 61, stated Anita Smith, 70, called social workers in May 2020.
Concerned family members reported Brockhill slamming-choking the toddler, lifting her by the throat and tossing her on a bed, threatening to remove her hair.
In the nine months before Star's death, Star's father and Smith's mother both referred him. Her great-was grandfather's closed days before she died.
Her injuries were ‘utterly catastrophic' and ‘unsurvivable', doctors said on September 22.
Brockhill claims she was in the kitchen making coffee when she heard a ‘bang' from the living room, where Star was playing with three other children.
She says she came out and found a boy standing over a crying and sick girl.
During the 15-minute delay, officials discovered that the flat had searched for ‘shock in newborns' and ‘how to bring a baby out of shock'.
Prosecutors claimed Star's injuries were too serious for a kid, causing considerable damage to her abdominal cavity from a punch, stamp or kick.
Jurors also heard that she had various markings on her body that indicated she had ‘suffered a lot of major injuries throughout her brief existence'.
The pair filmed many horrible acts against the girl and distributed them to others for entertainment.
Brockhill sometimes added dramatic music and captions to Star's film.
Both women laughed as they videotaped the girl falling from a chair or down stairs.
Brockhill found the clips amusing and compared them to You've Been Framed.
Mr Fawcett, Smith's grandfather, characterised Brockhill as ‘pure evil' after the judgement.
‘She came out of hell and shattered our family,' he claimed.
‘It's horrible since there were five referrals,' said Mr Fawcett, 61. Nobody did anything.'
‘Star was let down and we all want to know whether anything could have been done differently,' said Susan Hinchcliffe, leader of Bradford Council.
frankie Story SWNS SWLEstar. One of her lovers' 16-month-old baby girl and sought to blame a toddler was found guilty of her murder. Savannah Brockhill, 28, was found guilty of the murder of Star Hobson by a unanimous jury today. After three days of deliberation, Star's mother, Frankie Smith, 20, was found guilty of causing or enabling the death of a child. In her final remarks, Dame Justice Christina Lambert QC thanked the jury members for their service over the past ten weeks.
‘Bradford Council executives should hang their heads in shame,' said Keighley and Ilkley MP Robbie Moore.
The judgments came less than a week after Arthur Labinjo-Hughes' stepmother, Emma Tustin, was found guilty of his murder.
After Star's death, the Department for Education warned it would not hesitate to take away children's services from Bradford Council if required.
Smith screamed violently when the judgments were read in the glass-fronted courtroom.