Mothers Against Murder and Aggression chairman Amanda Everit said: 'We are astounded to learn these two women are in a position where, one would imagine, they are still able to openly associate.
'They not only murdered a defenceless little boy after what appears from the evidence to be sustained and prolonged abuse of him and other children but they further conspired to ensure a seven-year-old child would take the blame for their heinous act.
'This story will impact on the father and extended families of these children.'
After sentencing, it is believed the couple will be separated, with one staying at Cornton Vale while the other is sent to a female wing at either Edinburgh, Greenock or Grampian.
However, the Scottish Daily Mail revealed yesterday that it is likely the pair will be allowed to visit each other.