Am I screwed by not being able to force my "friend" to move out?

I invited a friend, down on there luck, to stay with me rent free as to get back on their feet. After 4 months with no job and zero effort to make things better, I told her she had to pay me to stay here any longer, $250/month. She stayed two months paying me and then the 3rd month she was unable to. At this point I told her she didn't do anything to better her life in 7 months of staying with me and she had til the end of that current month to leave(giving her a whole month to figure things out). By the end of the month she had disappeared, leaving the vast majority of her belongings and still holding onto a key to get in. After 2-3 weeks of being gone she showed up as after one day I confronted her on why she was here. She then threatened to screw me over since I am leasing the apartment and most likely have broken my lease by having her here. She also said I have to provide an eviction notice through the court in writing and even said go ahead and call the cops, they will tell you the same. There was no written agreement between the two of us on anything. I do plan to talk to the leasing office first thing in the morning, in hopes they can resolve this for me.