yes it absolutley is. I would talk to your guidance counselor at school about it or a teacher you trust and they will be able to connect you with resources and contact child protective services. however, if you arent honest about what she has done its possible that child protective services wont do anything (because I'm sure she will lie about how you got bruises). for example, I had a friend who as a child when child protective services were called somehow convinced them that she had bruised herself everywhere. I wish you luck