Setting out the case for the Attorney General, Tom Little QC told the court that on numerous occasions Smith had failed to seek medical help for her daughter when she suffered injuries at the hands of Brockhill.

The court heard that when Star was eventually beaten to death there was an “inexcusable” 11 minute delay in calling the emergency services.

Mr Little said: “This was not a case where the offender was so racked with guilt and pleaded guilty at the very first opportunity, remorseful from the outset about the loss.”

Dame Victoria Sharp, President of the Queen’s Bench Division, said the evidence showed that Smith had treated Star with such “cruelty and disregard” that this was not a case in which any weight could be given to her daughter’s loss as a mitigating factor.

In a statement issued after the judgement, the Attorney General said: “This is a tragic and extremely upsetting case and my thoughts are with all those who loved Star Hobson. 

“This case involved prolonged and multiple cruelty and neglect, deliberate disregard, and a failure to take any steps to protect or seek assistance for her before and after her murder. 

“No sentence can reverse this tragedy, but I welcome the decision to reflect the gravity of this offending by increasing the sentence today.”

‘Little to be said in mitigation’

Dame Victoria, sitting with Mr Justice Sweeney and Mr Justice Jeremy Baker, found that the sentencing judge had been wrong to reduce Smith’s sentence from the starting of nine years and said in fact such were the aggravating features that it should be extended further.

Dame Victoria said: “There was little, if any, to be said in mitigation. In our judgment no less a sentence than 12 years would meet the justice of this case.”

The judge said Star was “particularly vulnerable due to her very young age”, and that “self-evidently, Miss Smith was in a position of trust”.

Smith, who was said to have a low IQ, appeared at the Court of Appeal in London on Tuesday via video-link from HMP New Hall, wearing a grey top.

Last year, Bradford Crown Court heard how Star was subjected to months of abuse at the hands of Brockhill and Smith before she was eventually killed.