Nesta Yende was speaking outside the Springs Magistrate's Court where Yende's lover, David Ngwenya, appeared briefly in court.
Ngwenya - a technician at Eskom - is accused of killing Yende.
His case was postponed to September 18 for further investigations.
The 43-year-old, who was denied bail last month, had also changed his attorney.
A small group of women protested outside court, with some saying "Rot in jail, David".
During his previous appearances, the court heard that Ngwenya did not act alone, but with two suspects who are still at large.
Irregularities at work
"I am still in pain. Every 17th of every month I remember how my child was found decomposed," said Nesta.
Ngwenya allegedly murdered Yende, after he suspected that she would "spill the beans" on his involvement in a copper cable theft syndicate.
Yende, who was also an employee at Eskom, allegedly became aware of this and had allegedly told her mother they had heated arguments about irregularities at work.
Ngwenya is accused of injecting Yende with a substance, before striking her head with a crowbar and subsequently suffocating and strangling her after a struggle.
According to an investigating officer into the case, a witness - a sangoma - had come to the police station after the suspect and two others came to him and allegedly told him details about the commission of the crime, asking for a cleansing ceremony on two occasions.