I am thinking about kicking one of my bestfriends girlfriend out of our house
Why do you want to kick her out?
She is being a total bitch to me lately.
You don't have to live with people you don't want to but you shouldn't kick them out like that. It will lead to problems with your friend if you kick out his girlfriend, it would be better to talk to him first.
It's okay. She will be fine and eventually find another place to live. I think she is the kind of person who will just get kicked out in life.
Ask her why she has been in a sour mood lately and if you can do anything to lighten her up. People aren't grumpy for no reason, so showing you care might convert her to being more apologetic towards you.