The matter was postponed to Thursday for a formal bail application of the 18-year-old mother, Constable Zanele Vilakazi said.
She was kept in custody. The other two, aged 18 and 19, were released on a warning.
The mother was five months pregnant and took pills to induce early labour on Thursday evening last week.
“Shortly after taking the pills she gave birth in the toilet. She could not flush the foetus because it was big.”
She allegedly wrapped it in plastic and hid it in the back yard in her Bronkhorstspruit home.
After asking her friends at school for advice the following day, they allegedly decided to burn the foetus.
A school friend who was not part of the incident told her mother that her friends were planning to burn a foetus. The mother called the police and the women were arrested shortly after the incident.