Debbie,
I have known Mary of M&M for about 6 years, and she is a wonderful person. I have done some (limited) business with her, and always found that she was honest and committed to her clients.
I'm not sure if Mary Stephenson is still a rental agent, but she too, is top notch.
Just tell your friend to be very diligent in selecting an agent, as I have also had some TERRIBLE encounters.
Good luck.