A woman accused of stabbing her two young children more than 200 times as they tried to fight her off was charged Friday with two counts of first-degree murder.

A heavy bandage covered Tonya Vasilev's left wrist and hand as she stood in court Friday afternoon and answered the judge's questions in a soft, shaking voice. The judge appointed a public defender to represent her and ordered her held without bail.

Assistant State's Attorney Richard Karwaczka (search) described for the court the scene that Vasilev's husband found when he and a friend walked into the family's suburban Chicago home around 9:20 Wednesday night.

In the kitchen, Nikolai Vasilev spotted his 9-year-old son, Christian, lying on the floor in a pool of blood, Karwaczka said. The father scooped him up and carried him to the front door, where he frantically called 911. Then he and the friend started up the stairs.

At the top of the stairs, they found the Vasilevs' 3-year-old daughter, Grace, dead from stab wounds, the prosecutor said.

"Right next to Grace was the defendant, Tonya, sitting there with a knife," he said.

The 34-year-old mother was taken to the police station for questioning, where she "admitted stabbing her son and daughter at their residence," Karwaczka said.

Autopsies on the children showed each had been stabbed at least 200 times, he said.

Emergency crews tried to resuscitate the boy when they arrived, but they couldn't save him, Hoffman Estates Police Lt. Rich Russo (search) said earlier Friday. Inside the home, he said, officers found several knives believed to have been used to kill the children.

"It really doesn't get much worse than this," Russo said.

He would not discuss a possible motive for the killings or confirm published reports that the mother had been treated for mental illness in recent years.

The autopsies showed that both children tried to fight off their attacker, Russo said.

The attack in the home 30 miles west of Chicago came shortly before the five-year anniversary of a house fire that killed the couple's 3-month-old daughter Gabrielle when they lived in nearby Elk Grove Village. Foul play was never suspected, but Elk Grove Village Police Deputy Chief Larry Hammar said authorities were reinvestigating after the stabbings.

The day of the fire, Tonya Vasilev had left her daughter in an infant carrier in the laundry room of the home while she went to check on another of her children and noticed smoke coming from the window a short time later, according to Elk Grove Village police.

She tried to run back into the home twice, but was pulled out by a neighbor and firefighters, Hammar said.

Nikolai Vasilev, 36, had immigrated to the United States from Bulgaria in the 1990s to become a minister, said Stan Tanev, pastor of the Bulgarian Evangelical Church of God (search) in Des Plaines where Vasilev had served as pastor until about six months ago.

The couple met at a Bible college in North Carolina, married in 1994 and came to the Chicago area in 1995, Tanev said.

He said Nikolai Vasilev recently left the Des Plaines church to start his own congregation.

"We decided it was much better for us to work apart," Tanev told the (Arlington Heights) Daily Herald. "He was very sincere, very openhearted."

A preliminary hearing for Tonya Vasilev was set for May 20.