If Amber was a normal weight, she would be passably pretty - not pin up material but certainly not ugly.
But that isn't the case. By her own words, she's been obese from a very young age. She has never taken proper care of herself. Her diet is 99.9% garbage. She doesn't value fresh air, exercise, a stable routine; none of those or the many other ways adults look after themselves properly & her habit of not engaging in preventative care currently has her facing a situation no sane person would want to be dealing with.
Let's leave the cancer aside & pretend Amber wakes up, starts a sensible, long term diet for weight loss, slowly increases her physical activity & deals with all her health issues - known & unknown. Fast forward say... 3 years. If she's been consistent with her diet/exercise efforts, she might be down to 200 lbs. & if that seems miserly, I'm considering her lymphoedema. I have no idea how that will react to proper diet/exercise.
So let's put her at between 180-200 lbs. Fat beneath the skin of the face & neck is a Magic Eraser for wrinkles. If that fat goes away, she's not only going to have a large amount of loose skin but every wrinkle she's working on & she has a lot of light forehead lines already will age her decades.
She's not going to be able to achieve "in her 30s pretty" without a lot of plastic surgery. We don't know what's lurking under all that fat. Is her skeleton permanently messed up; can she ever walk normally? How much skin removal will she need? What facial procedures might she decide she needs, (other than idiotic lip plumpers), to look as good as she thinks she should.
I don't doubt many in the many hate groups would love nothing better than to see her remain unattractive but I suspect many if not most, are giving a fair assessment of what she might look like after a large weight loss.