Noluthando Nomavayi , 37, from Delft in Cape Town drenched her two sons with paraffin and set them alight when she discovered them smoking cigarettes in May 2011.
The older son survived the vicious attack but the younger one suffered 90 per cent burns and died at the Red Cross Hospital in Cape Town six weeks later, Sowetan Live reported.
Judge Vincent Saldanha said: ‘[The deceased] and his brother were much-loved and spent most of their time playing soccer in the confines of the family home.’
He lamented that Nomavayi’s nine-year-old son’s dream of becoming a doctor had been dashed.
Reports from various social workers and clinical psychologists showed that Nomavayi suffered from depression and had twice attempted suicide.
It was revealed that her mother had abused and neglected her as a child and she had been kicked out of her home when she fell pregnant at 16.
Nomavayi was convicted of murder and attempted murder.
Her surviving son is in foster care pending a Family Court inquiry.