We just moved in to the apartment in May and she moved out this month. she did not give any notice to the apartment management
Real Estate Attorney
You sue her in small claims court for reimbursement of her portion of the rent that you are now responsible for.
Chapter 11 Bankruptcy Attorney
Each party remains liable for the full amount on a lease. If one party leaves, there may be liability to the other, depending upon the circumstances.
Divorce / Separation Lawyer
I agree with Mr. Hawkins and Ms. Smith. You personally will still be liable for the full amount of the lease but may be able to sue your roommate for half of that amount. Small Claims court is definitely the way to go for this type of case. Try to resolve the matter out of court first by sending a letter to her or making a phone call, and if that doesn't work, file a complaint.