She may have had a less invasive weight loss surgery. My sister in law did and she lost weight very quickly, unfortunately for my sister in law,she wasn't disciplined enough and did not exercise enough to keep her weight off, and she ended up gaining some of it back.
My sister in law was overweight, but she probably wasn't 100 pounds overweight, but I don't think with some of the less evasive surgeries, you may not have to be that overweight anymore.
I am not sure, and I am not saying this is what she did, but it certainly could be a possibility, I suppose....Whatever it was-she looks phenomenal!