I guess that my first response to someone claiming that they lost 100 lbs in a few months would be skepticizm. Add on not having a fill, and I'd be even more skeptical. It's not impossible to lose 100 lbs in a few months, but even with the band, it would be an incredible effort.
It's most definitely possible to lose large amounts of weight without of WLS, lots of people have done it, and I have too. I just couldn't keep it off. My learned eating behavior always derailed me, and the weight came back with a vengance.
I think that one of the reasons that I've been obese for my entire life is just the way my brain is wired. I know that eating too much is bad for me. I know that it's caused health problems for me and members of my family. Intellect has very little to do with the problem. I'm an overeater, and I need this band as a tool to make me uncomfortable when I try to overeat.
Whether to have WLS is a personal decision. Each of us have to weigh the risks, benefits, and the potential for success or failure. Your friend has to understand that in order to be sucessful with banding, she needs to be committed to that success. It's no magic bean.
Bryan