Stella its entirely possible but it depends on a lot of factors, the biggies are your age, your genetics, and your body's addictiveness/ resistance to hormones
I have had no other surgery's other that SRS and don't intend to have any other's, for reference I started HRT at 20, I was 120lbs then, now I am 148, but I was up to 198 at one point 2 years ago.