According to the arrest affidavit, a fight happened between Rivera and family members early Sunday morning at a home in Orange County, Florida.
Investigators said in the arrest report that Rivera admitted to killing her daughter to prevent her from having sexual relationships with men.
According to the affidavit, the mother said she believed her daughter was having sex with men because she smiled "different."
"Rivera stated she believed with her actions that her daughter is now in heaven," the affidavit said.
Orlando police said when Rivera arrived at the hospital Sunday morning, she became combative and pulled out a knife when trying to get medical help for her daughter, who was dead in the vehicle. Rivera was taken into custody and the hospital was under a brief lockdown.