Legal Question in Real Estate Law in Maryland

You will have to go to court and file a partition action. This type of suit asks the court to appoint a trustee to sell the property and determine how to divide the proceeds (if any). In addition to the cost of the suit and the trustee fee, you may not do as well as a private sale using a broker. If your sister won't or can't buy you out of your part, explain this to her and maybe she'll realize that it's in her best interest in the long run to sell.