My Sister might be evil !?

My sixteen year old sister was a smart girl. Had a lot of friends and was real nice she gave money to the poor and volunteered at the animal shelter so last month my family and i moved to an old house and it’s nice and clean and Great. one night my sister woke up screaming and now she’s biting people claiming she i seeing mary giving birth she says that she is liberace or puck something like that she talks about death and Hell all the time. she got in a fight with the toughest girl at school and won the girls face was scratched up and there family pressed charges.We are Catholics and sunday when we walked in church my sister screamed like a demon a high pitched one too she ran out when we caught her she was not my older sister anymore What is wrong with my sister?