How do I obtain gap medication for my sister?

Sorry my answer wasn't so helpful.

Actually, I am dealing with the Social Worker. They are providing all the medications except for the anti anxiety meds and pain meds. Although I understand that this is not what the emergency room is designed for, I just don't want to wait until she has an anxiety attack to go there since we are in a rural area, approximately 45 minutes to an hour from the nearest emergency room. I thought the physician should have ordered that medication for her to have until she could see her new doctor in a week and a half, but they told me they don't do that.

Who is the person at the nursing home who is coordinating your sister's transition from nursing home care to home care? That person might be able to help with this. If you can not identify that person, you might ask to speak with the Social Worker or Director of Nursing. It usually takes a physician's order to get discharged from a nursing home. Ask if orders for those medications can be part of the discharge orders. Those orders could be sent to a pharmacy and the medications dispensed to you at the pharmacy. A nursing home isn't able to dispense medication. Using the emergency room for this is not the way to go. This is not an emergency and your sister's insurance might not pay for the ER for non-emergency care.