Authorities arrested Rosa Rivera, 28, on Sunday in Orlando after she arrived at the Winnie Palmer Hospital for Women & Babies carrying the body of her daughter, Aleyda Rivera, in her car's passenger seat, WOFL reported.
Officials said the incident began at a home on Citadel Drive, where Rivera had accused her mother's boyfriend of having sex with her daughter. Witnesses told detectives the child denied having sex with anyone.
Rivera initially denied stabbing her daughter but eventually admitted to killing her to "prevent her from having sex with other men", police said.More news: Nick Foles is signing with Jaguars
Lt Diego Toruno, a spokesperson for the Orlando Police Department, said Rivera became combative with hospital staff and pulled a knife on them, causing the hospital to briefly go on lockdown.
Following an investigation, Rivera was charged with first-degree murder.
Officials said Rivera then harmed herself, resulting in the cuts to her arm, before she arrived at the hospital. She also had a defensive wound on her right arm.
Rivera told authorities she stabbed the girl while in the vehicle.More news: United Kingdom government claims to win Brexit deal changes in last-minute talks
Rivera is now being held with no bond.
Security detained Rivera when they observed a knife in her hand with a red substance on it that was consisent with blood, police reported.
The woman told authorities she thought her daughter was sexually active because she "smiled different" even though she never walked in on her having sexual relations with a man.
Rivera did not answer reporters' questions as she was transferred from the sheriff's office to the Orange County Jail, reports the Orlando Sentinel.More news: Rams to Sign Safety Eric Weddle to Two-Year Contract