How do you deal with a violent 8yr old?

my little sister is very violent and uncontrollable. for instance she bit me very harshly today and it left a scar. my mom has no idea what to do with her one of our choices was we could send her to my father and have my father deal with her because we cant handle her violent actions anymore and the youngest child is always being the one abused by her.... help or ideas on what to do?