Hi Roger
There are a lot of doctors that will prescribe pills for weight loss. Some of the medications are safe, and the doctor should monitor her to make sure she's losing at a safe rate, that her blood pressure and overall health stays normal, and that she eats properly. If the doctor just wants to prescribe the pills and send her on her way, then she should find another doctor. You never want to take chances with health. There are a variety of pills that can be prescribed, such as Meridia, Zenical, or phentermine. I personally would avoid phentermine at all costs.
If you are wondering if the doctor is legit, there is a website where you can check to see if complaints have been filed against him, but I can't remember where it is
Maybe someone else will know.