Co-Executives

My mother is co-excutive of her mothers will. She passed away 3 days ago and my mother is unsure of what to do. She lives in the house and took care of her mother and the will states that she recieves 3/5 of the entire estate. The estate is in maryland. Can the other co-executive force her out of the house? Does she need a lawyer? Is there a time limit to when the will is executed? Laws governing the actions of co-excutives? And what particular areas should I look up to try and help her? Also of interest, My grandmother gave her the house prior to dying ( there are atleast 5 witnesses to this) but as the other co-executive was finacial power of attorney and my mother medical power of attorney he kept forgeting to bring the deed to be signed over. My mother is afraid of losing her home, how much time she has and what particular rights she has. Can you please help?