A 12-year-old Florida girl is facing felony charges after authorities claim she used a classmate’s account to send a chilling threat to “shoot up” her elementary school. The girl is charged with making written or electronic threats to kill and unlawful use of a two-way communications device, both felonies, according to the Volusia Sheriff’s Office. Over the weekend, detectives received a report about an explicit written threat sent to a teacher at Louise S. McInnis Elementary School. In addition to threatening the teacher, the sender said they were going to “shoot up” the school on the last day of class, according to the sheriff’s office. While the message was sent from a student account belonging to a 12-year-old boy, detectives determined it was sent by his ex-girlfriend, who had his login information, officials said. A 12-year-old girl is charged with two felonies after allegedly threatening to commit a school shooting.…