Continuing Reservation

I have a reservation under my DVC account starting on a Monday. A friend had banked points on her DVC account that needed used so she booked me an extra day, Sunday. I called and asked to have that Sunday reservation continue into my reservation so we don’t have to switch rooms after one day. Does anyone have any other options or ideas, or should I be doing anything else to get the same room? I didn’t realize this would be so difficult, as the Disney cast member told me nothing is guaranteed that I could just put the request in? Any advice much appreciated!