Unsupportive Wife

I am dealing with since I am new to weight watchers that my wife is not supportive in my attempt to get healthy.  She is someone who can eat whatever she wants and never gains weight.  She has the attitude that I can lose 30 lbs in a month.  She thinks day to day you can see your stomach shrink and not realizing it takes time.  I am not sure what to do get her to understand.  Anyone every deal with someone that is not understanding and how hard it can be to lose weight.  

Erik