My sister told me she wants to una|ive herself what should i do?

That's why i hate the internet so much. My sister (she is 13) is getting braces And alot of teeth removed beacuse she still has baby teeth when she shouldnt at this age. She really didnt want to had this braces, my mom said she was crying,shaking,And scratching herself when she got told that she will have braces. Late at night she went into my room And cried as i comforted her. She told me she will Una|ive herself cause everyone would make fun of her (she used to get bullied before) And i took her phone yesterday And saw she looks at all those memes that make fun of pepole without teeth...i really worry about her. What should i do?