ORLANDO, Fla. — A woman accused of stabbing her daughter to death told investigators she killed the 11-year-old to keep her from having sex, authorities in Florida said.

Rose Alcides Rivera, 28, pulled up to a hospital in Orlando asking for help for her daughter on Sunday morning, but the girl was already dead from multiple stab wounds, sheriff's investigators said. Then, they say Rivera pulled a knife on hospital workers before being arrested.

RELATED: Stabbing suspect shot by Waco officer dies, police say

She later told investigators she killed her daughter to "prevent her from having sex" with men, authorities said. She is charged with first-degree murder in the death of Aleyda Rivera.

The mother told first responders, "My baby is gone," the Orlando Sentinel reported. The child had 15 stab wounds to her back and a defensive wound on her right arm.

RELATED: Man jailed in stabbing death of child

Orange County Sheriff's investigators said the incident started early Sunday when the mother took her daughter to the home of a man and accused him of having sex with the child. Witnesses told detectives the child denied having sex with anyone.

An arrest report said Rivera first denied stabbing the girl but eventually admitted to killing her. "Rivera stated she stabbed her daughter while in the car, and while stabbing her she was attempting to make her more comfortable," an investigator wrote in the report.

RELATED: Capital murder charges filed in deaths of three kids -- including infant -- in Texas City

The mother told detectives she believes her daughter is in heaven.

According to the report, Rivera said she didn't see her daughter having sex with the man, nor did the girl tell her she was having sex.

Rivera had a superficial cut on her arm, which authorities believe was self-inflicted.

A lawyer wasn't listed for her on jail records.

Popular stories on KCENTV.com:

RELATED: Woman dies after rock from overpass crashes through windshield, police say

RELATED: 'She won’t be put down': Wildlife World Zoo says nothing will happen to jaguar that injured woman

RELATED: Agents seize $77 million of cocaine at New York-area port