Kimberley Hainey, 38, was sentenced to at least 15 years for murdering her son Declan and hiding his body.
She has always claimed she found him dead in his cot in her home Paisley, and that she played no part in his death.
Declan's body was found in March 2010, eight months after he was last seen alive. Experts were unable to establish a cause of death.
However, forensic anthropologist Professor Sue Black, of Dundee University, told jurors at Hainey's trial that marks on his bones were caused by malnutrition.
At the Court of Appeal in Edinburgh, defence QC Edward Targowski said the so-called Harris lines could be explained in other ways that did not rule out death from natural causes.
Lord Clarke, sitting with Lords Mackay of Drumadoon and Drummond Young, said a written decision would be given at a later date.