Should I be offended???..because I am
I wouldn't be offended. You said you didn't tell her you were have WLS. She's just concerned and wouldn't you rather have someone in your family address you being overweight. My sister always wanted me to go to the gym with her and I always made excuses. I probably felt a little offended at the time, but after thinking back now, I'm glad she offered rather than talking about me behind my back.
I would call her and tell her the decision you have made and tell her you appreciate her thinking enough about you and your health to try and help you out.
I don't think that you are offended, I think you are embarrassed that someone who has remained quiet about the weight issue said something. The same thing happened to me with my favorite cousin and I realize now that my pride was bruised. But anyway, I noticed that you haven't posted a date or anything so i guess you haven't been approved....take her up on the offer and use the Jenny Craig or NutriSystem as a part of your 6 month diet before surgery. At least you won't have to pay hundreds for the weight loss attempts.
Hear hear to free food. Don't email her back just call her and talk with her. Sometimes people freak out when they don't know the facts. Explain it all to her and if she doesnt get it then take the free food and still have your surgery honey. Then when she sees the new you, she'll become a believer.