My weight was always on the low side, but once I hit 45 it just ballooned. Thyroid checked out OK, but no help from doc for the 1st 4 stones despite pleas. Finally a referral to the weight clinic who were very dismissive - they do not think 14 stone is excessive enough to bother them. Lots of weight related medical issues later, I got a referral to Slimming world. Time that help was available before you hit obesity - would save a lot of NHS money.
The new drugs will only help those who overeat.
Tell her that if she is worried, she should consult her doc though, who will a) see if she is actually overweight, b) look for any medical reasons c) give better advice on help than I got