jbug, ususally something can only hurt when it is somebody close to us. We give certain people in our lives a status of importance. My grandparents also did somethings that were very uncomfortable to me when they were in their 80s. At first, I was very upset. Then, an understanding of their mental state put my hurt emotions to rest.
It is obvious you care deeply about her, but, you are intelligent to understand her health situation also. You are doing the right thing, by putting her opinions into perspective. If you can remind yourself that her actions are also out of concerns for you, it might help to calm the feelings of frustration you have.
The most important opinion is that of yourself. You are taking on this lifestyle because it is a necessary health requirement. The fact that you decided to take on this lifestyle, no matter what others say or think, means you are rightfully putting yourself and your health first. That is very positive, and admirable. Besides, I have known people who seem to criticize in our presence all the time and found out that behind our backs, they speak highly of us to others. It seems odd that they don't voice the same praise onto us, but it is a quirk of nature.
Keep your chin up hun. You are doing great!! Two thumbs up.