Cushings disease for younger dog boston terrier

My B'T was recently diagnosed with cushings, I think we were lucky because the first signs were a difference in the skin. She is now on her second month of vetoryl and her second set of blood work is in the normal range.  She  is a rescue and according to what we were told she would 5 now.  Our Vet doubts that but does not believe that she is older then 10.  She has started to get the belly and hair loss. Our vet informed us that it will take a couple of months to see positive results in her skin and belly etc.. I have been searching the internet insanely....i have heard really positive outcomes (close to a normal life) and then more negative outcomes (1- 2 yrs).  I most always trust my vet, she seems really optimistic, but I am afraid that it is false.
Help me with some advice and opinion

thank you for anything you can offer