She broke the lease "in your opinion?" I don't agree with your opinion. If you just signed a 6 month lease, why do you need to move out by December? I you have a lease, the new owner will have to take the house subject to your tenancy - or the sale will have to wait until your lease is over. Unless the lease has a provision allowing it, she cannot terminate the lease for this reason.
I may be guessing or not licensed in your state. No atty/client relationship exists. I earn my living collecting points for "helpful" answers.
If you signed a six month lease, you are obligated for six months. The fact that your landlord is selling the house does not affect your obligations. If you did not want to have to move in December, you should not have signed a lease that ends in December.
This answer does not constitute legal advice and does not establish an attorney-client relationship.
Selling the property is not an automatic breach of your lease agreement. You should read your lease carefully to see if any of your landlord's actions rise to the level of a breach. Most likely you are obligated to pay through the end of your 6 month term, unless your lease specifically identifies the sale (or attempted sale) of the property as violation of the lease.
If you liked my answer, please rate it "HELPFUL" or "BEST". Also, you can contact me for further detailed questions and answers at 412-904-5305. **DISCLAIMER** Michael I. Werner is licensed to practice law in the Commonwealth of Pennsylvania. This answer is based on general legal principles and is not intended for the purpose of providing specific legal advice or opinions. This answer does not constitute the establishment of an attorney-client relationship. It is always recommended that you consult with an attorney prior to taking legal actions on your own.