The first question we need more info about is why won't she transfer the property? Is the Executor thinking of selling the property? Does she have the authority to do so? Is the Will explicit on what is suppose to happen to the property? Depending on your answers to the above questions - you can file a Petition to compel sale of the property if that is best for all concerned. Alternatively, seeking the removal of the Executor for her delay may be considered by a Judge depending on the facts of the case. Go see a probate attorney to resolve this for you.
My answer is not intended to be giving legal advice and this topic can be a complex area where the advice of a licensed attorney in your State should be obtained.
The heirs need to get together and hire an attorney to file a petition with the Court to force the Executor to distribute the assets.
NOTE: Mr. Fischer is an attorney licensed to practice in Pennsylvania. He can be reached at 610-269-0900 Ext 2 or email@example.com. This answer was prepared for educational purposes only. By using this site you understand and agree that there is no attorney client relationship or confidentiality between you and the attorney responding. This site should not be used as a substitute for competent legal advice from a licensed attorney that practices in the subject area in your jurisdiction and with whom you have an attorney client relationship. Frequently the question does not include significant and important facts and time lines that if known could significantly change the response. The law changes frequently and varies from jurisdiction to jurisdiction. The information and materials provided are general in nature, and may not apply to a specific factual or legal circumstance described in the question or omitted from the question.