I think we need a picture of this girl
Morbidly obese and beautiful face are not things I have ever heard at the same time before. To say someone is so overweight they are going to die from it.. that's a bold statement. Usually someone of that caliber of weight is going to also have a puffy face and 1+ extra chins. In other words, if she dropped 300lbs, you wouldn't even know who the **** she was anymore.
Seeing as your a gym rat, I gotta feeling your definition of morbid is a little different than the rest of us. Give me an idea of what you would guess her height and weight to be.
She's 19, I'm 23.I don't know how old you are but age has a lot to do with it. if you guys are young and she looks like that then she will probably struggle in the later years to keep the weight down. a low motivated person will only get worse till it is too late. if she is older AKA 27-30 and she looks like that with low motivation than I would say her weight gain has been gradual and probably not have a real hard time sliming down or even staying the same shape with some exercise. now that I am in my 30's I will say staying in shape is tough and I was thin up until I was 28 so just think for the future boss.
also girls tend to gain weight in a relationship.