well, when i came home from school today i did my homework and after that a started screwing around on newgrounds, then my sister comes in. she complains about her homework and that she cant write is cursive,so then i said "oh comon, yes you can." trying to be encouraging, she yelled at me "NO I CANT!!!!!!!!!!!" so the she started hitting me so i hit her back and triped her to defend my self and get it of of me. she starts screaming and crying and yelling. and now she is not talking to me and being a total pill. what can i do? ( this actually happened a little while ago)