NEW YORK — A Manhattan nanny accused of stabbing to death two small children in her care before trying to commit suicide pleaded not guilty Wednesday in a hospital court hearing.

"I ask you to enter a plea of not guilty on behalf of my client," Yoselyn Ortega's attorney said at the hearing, convened at the hospital bed of the woman, who remains in a serious condition after allegedly slashing her own throat in front of the children's horrified mother.

Her lawyer, Valerie Van Leer-Greenberg, said Ortega "sustained serious medical injuries and mental trauma." The judge said she should remain under suicide watch.

The Dominican woman has been charged with murder in the first and second degree, meaning that if convicted, she could face life in prison without parole.

Police say Ortega, 50, was found by the children's mother in her luxury apartment's bathroom, with six-year-old Lucia Krim and her two-year-old brother Leo already fatally stabbed. The nanny was bleeding from her own throat.

The horror of the October 25 bloodbath in a posh neighborhood next to Central Park shocked New York, where babysitters and nannies are heavily relied upon by parents trying to juggle jobs and family life.