She's discouraged and upset and isn't even interested in going through the process anymore. 

Honestly, it sounds like she was not mature enough to have surgery in the first place! Alright, I'll say it,and you can pass it along to her (or not):

WTF??!! Jesus Christ, girl! Stop being a ******g baby! At four weeks, you're hardly out of the post-op diet stages. If you want MAGIC, go see David Copperfield. WLS is not a magic wand!

It took you way, WAY longer than FOUR WEEKS to get obese, and it will take a HELLUVA lot longer get get "un-obese." This is a LONG damn road, and if you're sitting on the pity pot after a MONTH, you are in for a world of misery.

 I know its been said before, but I really wish we had a like button! I researched the band for a year and a half then I dr shopped for 6 months so I can honestly say that the only surprises I have had are good ones!  I guess if you see the commercials and billboards you might be a little pi$$ed off! No you cannot eat whatever you want and lose weight cuz if you could none of us would need wls! Its not an amputation, you don't wake up from surgery and your problems gone, its a LIFE CHANGE! Change your bad habits, learn your new normal and then worry about fills!

I understand her frustration because I was extremely hungry from day 2. However, at week 6 when I was allowed to eat whatever I could handle I ate steak. I sure wouldn't have done that after a fill that early. What I had to decide was that it might take me long enough to reach my sweet spot so that I felt my band was helping that I might just be done losing all my weight by that time. So be it. I could do that, albeit with difficulty, but I sure needed my band to help me keep it off. I had never been able to do that before. I had to be willing to work hard, and I was. Your friend needs to come to the conclusion that this is her big chance and that doing this will end in immense self fullfillment, and a huge jump in self esteem. A wls that did it all for me would not have given me that. By working my tool to the best of my ability I can be proud of my achievements and know that I can continue.

I have no idea whether this will help her or not, but the other thing for her to remember is that buyers remorse is so common ( I've heard it from people with all the proceedures) that it is nearly a given. Assuring her that even though she hates the thing right now she has it, has paid for it, has gone through surgery for it and has prepared for it. With that in mind it only makes sense to give it her best try and see what happens.

I'll pray for her, Sue

I have to agree with Bette B.  If she has that attitude at this stage, it sounds like her weight loss journey is going to be a particularly difficult one.  Hopefully, she can get remotivated and keep her head in the right place during this time. 

Everyone adjusts to change at their own pace and in their own way.  It's kind of you to want to be a positive support for your friend.  I know I wouldn't have made it through so many things without my friends- and I'm looking forward to meeting friends on OH who will share my experiences.  That is what ultimately may help her the most- to reach out to this community and share her frustrations.  Lots of different voices here.
Who is Jean M. and what is her book?