Good afternoon. I am Loren, a licensed attorney, and I look forward to assisting you.
Assuming you cannot reach an agreement with your sister, your remedy is to file a petition seeking a judicial partition. That is really your only remedy if you are at an impasse.
If real property is owned concurrently by two or more persons then any of the interested parties may bring an action to "partition" the property which, effectively, requests the court to physically divide or, alternatively, order the sale of the property and division of the proceeds. The action is called a Partition Action and for people with concurrent interests (currently existing) who have not "waived" the right to partition, this remedy is an absolute right. The demand for partition must be granted by the Court to such plaintiffs -- although the details of the order can vary widely. The "order" for the sale is typically an Interlocutory Judgment of Partition by Sale, either issued soon after the lawsuit is filed but sometimes not until all of the financial and legal issues are resolved.
Partition actions must be filed in the county where the property is located. Any person with an existing or future interest in the property may bring the action.
The court has broad equitable powers to protect the interests of all concerned, to prevent waste and to otherwise protect the interests of the owners. In a significant portion of the cases, one of the parties is in possession of the property, whether residing therein in a residential context or operating a business therefrom in a commercial context. There may be issues of fair rental value, payment of the mortgage, insurance, and maintenance expenses, or preservation and distribution of rental receipts. The court may require the parties to contribute funds to the operation of the property, to grant access to the property to various persons including the referee, and to make whatever other arrangements are necessary to preserve the asset and to separate the dispute over the property from the efforts to get it sold.