Roommate refuses to pay bills/told me she's moving out on a whim

My roommate told me one night at like 2 am in the morning she was moving out at the end of the semester (of college). She didn't pay the rent when she said she was going to for that month, she didn't pay the bills like she was supposed to, and she left shortly after telling me that, not before she stole some of my 200 dollar medications though. She left some of her belongings here, and now she's planning on coming back up to get them. I know Wisconsin law says I'm not allowed to keep them as she's still a tenant. (We have a Month to Month lease.) But, honestly I have nothing keeping her from just vacating and sticking me with all the bills and late fees she's accumulated by lying to me.

Honestly she didn't tell me until the second week in December that she was leaving, and we have a rule in our lease stating that we have to give notice on the first of the month to be gone by the first of the following month or we pay rent on that. So is she not legally binded to paying last months, this months, and next months? If so, how do I get her to pay? Do I really have to sue her?

[OHlandlord]

Yes, you will have to take her to small claims court to get your money back from her. Sue her for any back unpaid rent, the rent for the 30 days that she failed to give you notice for, any late fees, etc. That's the only way to get your money from her.