I honestly think this is something that people who have never been overweight CANNOT understand. It's something they've never experienced, so the lifelong struggle, the difficulty of being overweight, the constant uphill battle is something that they just don't know. Also, because it's a surgery, she's probably frightened something will go wrong. I think maybe if you share what you've gone through, maybe your sister will understand. I was shocked when my surgeon had me list all the diets I've been on over the years. It was a list of something like 20 diets!!! I also think if you get her to check out this site, she might see the number of very healthy and happy people who have had this surgery. Regardless, I'm sure they will come around eventually. Sometimes it takes people time to adjust.