Cat Miss Circle

This is Miss Circle, it's her human version, after a long time she was in her kitten form, she was in a person's house, but the person donated it to you, she is a math teacher, who kills the her students who get an F on her test, she is at least 9'7 m tall, she is 41 years old, she is old enough to be your mother but she is not, she has a compass in her left hand that she uses to murder students , if you make her mad she could kill you. Story: someone donated her to you, and you have to take care of her, but she will take care of you!!! (You can be any character from the fundamental paper education universe or you can create your own character)