ORLANDO, Fla. (WWJ/AP) - Sheriff's officials say a woman pulled up to an Orlando, Florida hospital asking for help for her daughter who had been stabbed -- but it was already too late.

"This morning at 10:51 am, Alcides Rivera drove her dead daughter to Winnie Palmer Hospital where Orlando Police Department officers were able to detain her," the Orange County Sheriff's Office said in a statement Sunday, accompanying a booking photo of the suspect.

She is charged with first-degree murder in the death of 11-year-old Aleyda Rivera.

The Orlando Sentinel reports the 28-year-old woman told first responders "my baby is gone." The child had 15 stab wounds to her back, and a defensive wound to her right arm, authorities told the newspaper.

While at the hospital, authorities said the mother was argumentative and pulled a pocket knife on employees before she was subdued and arrested.

She initially denied stabbing her daughter, according to an arrest report, but later told investigators she'd killed the child "prevent her from having sex" with men.

Sheriff's officials said the mother, Sunday morning, had taken the child to a man's house and accused him of having sex with the girl. The child denied it, according to investigators, and Alcides River then stabbed the girl while in the car.