a traitor type of friend

I am a girl and I am 14 years and i can't tell my name for some privacy,so the story based on real event and so let's begin In my school (can't tell name of school)I was in 6th std and I am a topper i always come first in class ,so a girl (can't tell) let her name be speaker because when she speak that's sound like very high like speaker and she is in 7th std So ,when the 6th final exam ends and holidays start I wanted to go one class ahead because when someone ask me which class I am in i said 6th so they said you don't look like you are in 6th you should be in 8th or 10th (I was tall) so that's why I wanted to go in one class ahead so I ask my principal to move me in one class ahead and my study is very good so it done ,and i am going to 8th std When the holiday finish I go to school and I am become her class mate now ,and there was 7 students including me 3 boys and 4 girl so she is and other girl let her name be patel they where besties and at first we become friends and later we become trio so,When speaker don't come school I can't enjoy because she 's talk too much and i get happy when I see her ,So ,one day we had english extra classes and we had to write on board roll number wise because that school supervisor is english teacher so her excuse is that ''i am busy ,you all write on board by yourself ok''.and not even explain the lesson on time and come late school also and explain the lesson at exam Time by taking extra classes,so let's continue so my roll no.is 3 and i am writing on board so boys are making fun of me(mean we are friends we are enjoying by roasting other)and she's all time laugh but patel didn't.she support me and didn't laugh and speaker tell boys please stop my stomach hurt .I was like why.i don't laugh when someone made fun of her but she I was very disappointed 😞