The 45-year-old woman who was arrested on Thursday in Mdantsane near East London for the murder of her husband, will now also be charged with the murder of his girlfriend.
The wife allegedly plotted the murder of her estranged husband and along with her two accomplices, barged into his house in the township's NU14 area on Wednesday night.
According to police spokesperson Captain Mluleki Mbi, shots were fired at her husband and he died on the scene from a gunshot wound to the head.
They later poured petrol on his girlfriend and set her and the house alight.
Mbi says she has since died from her injuries.
Captain Mbi says the accused was scheduled to appear in court on Friday but was admitted to hospital under police guard instead as she also sustained burn wounds in the incident.
Her two accomplices are still at large.
When the woman is fit enough to appear in court, she will face two charges of murder and arson.