There is great rewards to be had in having disabled people do things on their own. I was a CNA when I worked my way though the university. It would be far faster and easier to dress people than to help them help themselves. But there is much self esteem to be had by having them do as much as they can. The fact that your wife does go get her snack when she doesn’t want to wait shows she can do more on her own. That’s to be encouraged. It’s mentally strengthening to help yourself.