Lifting weights actually activates your metabolism leading to faster weight loss. What you should advise to that person is to replace her body fat with muscle. Women should not fear lifting weights to lose weight. Cardio alone won’t do.
Maybe she doesnt want to look muscular….Most women think it makes them look manly.
Surgery. If you want to do it naturally, then you’ll have to burn more calories than you take in. Plain and simple. Running, running and more running. I actually won’t recommend lifting weights at all, just aerobics and that’s it. It will take time and dedication and you probably won’t see results until 4 - 6 months, but you’ll eventually start losing weight if you do it the right way. Take care and good luck.