Please please HELP -- Need some advice

Ok, this is the situation. I just moved into an apartment in New York last October with some random person I met on Craigslist. The person I moved in with had just moved into the apt. as well and has been subletting the apt. from her friend (who's not living in the apt. and is living overseas). I'm not sure if she's on the lease or if it's only her friend's name. Just recently, she told me that she would be moving out in about three weeks on Feb. 15 (and pretty much, expected me to pay the last two weeks of Feb. on my own). I send her a reply stating that I also would be moving out on Feb. 15 contingent on 1) the receipt of her share of the utilities which are in my name, and 2) the receipt of my deposit. She has not responded or kept appointments we've set up to talk about the situation, so I'm pretty sure she's going to be a bitch about it and not pay me the large sum of money she owes me. What recourse do I have to get this money (other than small claims, b/c I had won a case in small claims in the past and never received any of the money). If I stay in the apartment without paying rent until I am compensated for the money she owes me, 1) what recourse can she take against me (we have nothing in writing).. she's threatening "another course of action" if I don't pay rent, and 2) I know that the landlord can evict me with a court notice, but can he sue me for the rent if I'm not on the lease? He may not even bother because the lease is up on March 31st anyways plus he still has their deposit. Please, someone tell me what is the best course of action to take.