How to get my roommate out

I'm 16 F and my "roommate" is 18f. She had moved in because of a domestic dispute with her dad. I was fine with it but now she won't leave. She had promised to leave in may (she got here mid March on my birthday :[ ). Everything was going fine until she admitted she is back in contact with her father. I know it is not safe for her to go back so I do not push that issue. She also has the money to gamble with her boyfriend buy vapes and get her nails done. But no way to get an apartment or to move in with her boyfriend ("His dad is to scary" her words) She needed a person to come sighn. She refused to ask her boyfriend, she did not ask her dad and she forgot when her mom was in town. I believe I will be the one moving out before her. I really think I need to move out so she can have the space because I am truly getting uncomfortable. She will have sex with her boyfriend while I am in the room and on my bed. I need advice please help. All advice appreciated (Please tell me if I am over reacting)