Defending Twin at School

this is my twin brother Noah I’m his twin sister we are 9 years old it’s our first day of school we are at school I’m more of the shy twin my twin brother is more of a talker because I’m the shy twin I get bullied a lot my twin brother doesn’t know and I don’t want to tell him so I don’t I keep it to myself eventually he finds out but I didn’t tell him he caught it happening when he walked in the hallway when he was going to the bathroom we are in different classes except one class we are in together but at that time we wasn’t in the same class he went to the bathroom and saw a taller girl then me that was in 5th grade and me and my brother was in 3rd grade well that bully girl took my book and started ripping the pages I just stood there with my head down while she was doing that I didn’t even try to stop her I was to shy to plus she was in 5th grade my brother came over and showed her who’s boss and hugged me and asked if I was ok