It's really hard to go from zero physical activity and terrible diet to eating well and sticking with a training regime. People who've lost a lot of weight know about it, but so does anyone who has gone from skinnyfat to shredded, or anyone who has gotten serious about a sport like distance running or rock climbing. You have to consciously choose to override certain habits until you've made new ones, and then once those are set you have to move onto others. You've got to stick with activities that you feel stupid or uncoordinated doing, and you've gotta keep at them long after the initial buzz of doing the right thing for yourself wears off.
She is so grossly obese that she has hundreds of pounds to lose before she is in a healthy weight range and she's permanently lost any chance at looking conventionally attractive. Her obesity hasn't just ruined her joints and skin, she's permanently fucked her endocrine system. She's cooked the systems that help her body detect when she's had enough to eat. If she somehow loses the weight without a drug like ozempic, she will be a hungry ghost with a body like a melted candle.
On top of all of that, she made a whole damn identity on why you should never have to do any of that shit, and it's bigoted as fuck to ask her to. So she can either feel like a failure selling out her previous ideology and grinding away for months on end to go from 350lbs to 285lbs, or she can feel like a failure stuffing her fat maw with hydrocodone and cupcakes while she blames the healthcare system for not supporting her. I know what I would bet on