In South Florida, my girlfriend is on a lease with only her name on it. She decided to get a roommate but no contract or any kind of form was ever signed. This girl is now very verbally abusive, extremely disrespectful (does not clean up after herself, invites friends over to stay whenever and for however lkong she wants without prior notice, screams and argues while on her cell phone in front of the house so others can hear, slams doors, uses and abuses the washer and dryer daily, keeps lights on all the time, turns the air conditioning down and leaves it cold even when nobody is home, etc.) and has also physically made gestures. The roommate keeps stating that she can never be kicked out and that since she used to be a cop in another stae that nobody will touch her.

This roommate needs to be kicked out immediately before this escalates, what can be done and fast?

The roommate has to be evicted in accordance with Florida Law - Guidelines for Florida Residential Eviction.

This site sets it out very clearly.