How to stop dogs from fighting?

My one Aussie pup insists on constantly fighting with her brother. Also, she chews on the furniture, wont stop barking, and keeps pulling down my sweatpants (she bites ans pulls). How can I stop this? I tried curling her lips under so she bites her lip when she bites things, but this doesnt seem to work. I love her to death, but I cant take it. Any advice or help?