WLS in the form of a gastric bypass or gastric soeeve, followed by loose skin removal surgery are her only prayers of ever getting close to a "healthy" weight. Regular dieting or Ozempic might get her into the 500's but she isn't going to get down much further without physically shrinking her stomach via surgery.
Side note: i, 42/m, started taking Zepbound (Ozempic + 1 extra ingredient) September of last year and went from 318 lbs down to 248 lbs., a 70 pound loss, by March or so of this year. Then i hit a plateau i haven't really been able to get past. To make matters worse, as of a month ago my insurance stopped covering Zepbound and i am now on Wegovy (Ozempic) and have actually gained a few pounds back to around 255 or so. On one hand this does show that these drugs aren't going to magically make all the SSBBWs disappear (they just might become BBWs) on the other hand it sucks for me because my goal was to get down below 200 lbs. and now that goal looks difficult to get to without an actual lifestyle change or surgery.