11 year old bit younger brother

[Exhausted0106]

Had the kids and their cousins in the living room together over the weekend for a sleepover, all going well until I hear crying. DD (11) had taken DS (7) by the arm and bitten him. Her reasoning: "he was bugging me". She was obviously reprimanded at the time. She is currently on her period, these started a year ago and she can be very emotional but I feel like this is not normal behaviour for a girl of her age. DS is so much smaller than she is and it worries me.

Not usual behaviour at all for a typically developing 11 year old. I know hormones are a factor but I’d be putting firm boundaries in place.
Sounds like she tried to justify it. She would be excluded for this at school. Human bites can be really serious as I’m sure you know but she may not.
Maybe she can learn to walk away or use some calming strategies for anger management such as controlled breathing, counting to 10 slowly in her head or clenching and unclenching fists by her sides.

I would tell her that if she bit anyone else at school she would be suspended as a bear minimum and as she is 11 and the age of criminal responsibility is 10 then the person she bit could go to the police over it. It is assault, don't mince your words with her, she has assaulted her brother. Teeth as classed as weapons.

Your 7 year old might disclose this information at school so if I were you I would be honest with them and tell school so it doesn't look like you are hiding it.

Your DD needs to understand that what she did is criminal and to never do anything like that again. Sibling abuse is unacceptable.

She needs to learn strategies to calm down. She knows she would not do this to a teacher or a friend and cannot blame her choices on her period or that he was bugging her so she was justified. None of it is acceptable.