I understand your frustration, but if you are the tenant and she is an occupant, you are responsible for the rent and if it isn't paid, you are risking eviction or at least damage to your rental record. If you purchased the furniture together you will have to resolve who takes what, but you don't want to try to hold onto things that are legitimately hers in an effort to get the rent. You can likely sue her for her portion of the rent if she fails to pay, but try to resolve the issue with her first. Also discuss the issue of replacing her on your lease with your landlord before you get a new roommate, or you could end up with an illegal sublease and both the roommate and your landlord coming after you.
You could sue your roommate for the back rent owed to you but essentially you will be responsible for any unpaid rent to the landlord since you are technically the tenant and she is not.
Answers to this question are for general purposes only and do not establish an attorney-client relationship or constitute legal advice