Elzbieta Plackowska Update: Ill. mom pleads not guilty to stabbing deaths of son, girl

(CBS/AP) WHEATON, Ill. - Elzbieta Plackowska, a Chicago-area woman accused in the stabbing deaths of her 7-year-old son and a 5-year-old girl she was babysitting, pleaded not guilty on Wednesday.

PICTURES: Cops: Ill. mom stabbed son 100 times, girl 50 times

According to CBS Chicago, the brief hearing was the first-ever televised court proceeding in the Chicago area.

The 40-year-old woman was arrested last month after police went to the Naperville home and found the children dead. Two dogs were also found dead at the home.

Plackowska has told investigators that the children had been jumping on the bed at the girl's home in Naperville. She ordered them to pray, then stabbed them both dozens of times as they begged for their lives.

The Polish immigrant told investigators she killed her son because she was upset with her husband and was grieving her father. She said she killed the girl because she was a witness to her son's death.

The judge set Plackowska's next hearing date for Jan. 4 at 9 a.m., CBS Chicago reports.

Complete coverage of Elzbieta Plackowska on Crimesider