She lost 106lbs in 4 months?
At a certain weight you are essentially fighting to keep that weight, so an effort towards weightloss for obese individuals can easily translate to some seemingly insane numbers for average people. It's really just thermodynamics, the people are larger, thus more resources needed to fuel the body, thus more calories are burned in a day.
That's something obese people should be made aware of because they will lose a ton of weight in the beginning and then hit a really hard plateau, it might seem impossible for them to lose weight following that initial loss, but in reality, their energy expenditure was just significantly higher before and they need to taper expectations, restrict calories further, and adjust for activities that can increase the expenditure heading forward.