Suggest Treatment For Back And Abdomen Pain

MY DAUGHTER IS FIFTEEN AND HAS BEEN HAVING PAIN IN HER LOWER LEFT BACK A FEW HOURS AGO, NOW HAS PAIN IN LEFT SIDE AND LEFT LOWER ABDOMINAL PAIN AND SOMETIMES GOES TO HER LEFT LEG, HAS CHILLS AND FEELS LIKE SHE HAS A LOW FEVER.WHAT CAN THIS BE? AND SHOULD I TAKE HER TO E.R?