Legal Question in Civil Litigation in New York

You and your roommate are jointly and severally liable under the lease; each equally responsible for the rent.

Furthermore, since your roommate has signed the lease together with you, and since you are responsible to pay the rent in any event, you may sue her for the balance payment of rent on her share deducted by any amount she paid for her portion of the refunded security deposit.

The small claims court may ask you what if any steps you took to mitigate the loss of rent from your roommate; for instance, did you try to find another roommate or did you try to ask the landlord for lower rent, etc. However, this is unlikely due to the liimited period of time remaining on your mutual lease.