Hello, before we start I would like to say sorry for any spelling and grammar mistakes, im on mobile and I cant seem to get auto correct on it.

So to start out I have a sister who is around 3 years older than me. We are both still teens but shes close to being an adult. We share a room and sometimes talk about things at night. We both got into a fight during one of these talks about a really stupid thing. She ended up saying im "either deaf or stupid". This went on with a few "are you sure about that"s before I said "im not the one in a recovery school". I was talking about how she had to be moved to a "special school" because of her grades. Next year we'll be in the same grade despite her being a few years older than me. She said its not okay for me to make fun of her but im pretty sure she shouldnt of called me stupid. Am I the asshole here or is she in the wrong?