No on the first question. She's a young woman who looks nowhere near her age now, in my opinion. If someone said she was late thirties, I wouldn't be remotely shocked. And I didn't think she was *floppy*, as you say, as many become after rapid weight loss. Why didn't that happen to her? Because even though she was obese to start, her body probably kept some of her fitness and she's young.
So no. She had deep lines that women have decades later. That says too much to me.
I am around a lot of athletes. And a few who exercise excessively (unlike professional athletes that have people monitoring their body/nutrition levels), and are very strict about eating low fat, have that look even if they didn't lose a great deal of weight. So her look wasn't about the huge/rapid weight loss in itself, in my opinion. Heck, there are a few weight loss doctors that have that look.
Look at Bobby. He's young too, although not as young as Rachel. He didn't have that look at all in his face, despite rapid loss.