Her ego feeds on ass pats the way cattle chomp down on grain in a feed lot. I can understand that those still in her corner want to encourage her but all that may accomplish is her starting to believe she can truly do this on her own.
If, IF she ends up genuinely working on & losing weight, a lot of issues are going to crop up where professional help would be truly valuable. If I were her, I'd be wanting fairly regular blood work to make sure I'm not inadvertently shorting myself of crucial micronutrients. Lower weight doesn't eliminate those risks, especially when you look at the crap she eats.
Physiotherapy. I can't begin to guess when the last time was that she was able to walk normally, with half decent posture & correct motion through the hips, knees & ankles. She may need help to learn to walk normally. Hell, even the highest caliber professional athletes often use physio to prevent injuries. She'll have a lot of body areas that need strengthening the correct way, especially if she eventually decides to become more active.
Proper physical workups throughout this process, first to get a baseline of organ & system functions, then to check on improvement & eventually to determine what's permanently damaged & how, (if), any of that can be mitigated.
And for the millionth time - therapy. She'll need to learn to see herself differently; realistically & needs to learn that as she changes, how those in her life might react & sadly, that's not always positive when people lose a lot of weight.
She had therapy & "self care" in her New Year's Intentions & no matter if she wants to admit it or not, cutting her hair, makeup & nail polish are the floofiest of fluff. Genuine self-care in the form of serious concern about her health is what's needed.