Nomsa Mudau was also arrested in 2018 after she had allegedly plotted, reportedly with the assistance of Ndlovu, to kill her husband, Justice Mudau.
That plan was thwarted when the alleged hitmen told Justice about the plot to murder him.
The two former police officers were initially charged for conspiracy to murder Justice in March 2018, the same month Ndlovu was arrested for trying to kill her sister and her children.
The case was, however, provisionally withdrawn and re-enrolled this year.
Nomsa has since divorced her husband.
The officer, who is out on warning, appeared in court last month heavily pregnant and stood in the dock alongside Ndlovu, who has been behind bars since 2018. Nomsa told the court she was due to give birth any day.
Both women, who did not look at each other, opted to use Legal Aid.