In that case, she was judging based upon someone's appearance because they were different. Once we realize that not everyone has to be depicted as what we call "normal" we may not judge others as much as we do, for something we simply cannot help.
Many people assume having a wheelchair, walker, cane, etc. makes you physically incapable of doing some tasks. While in a lot of cases, it does. We have laws and requirements that make it possible for anyone with a disability that needs a walking assistance, to access almost everything that your average person could. In most circumstances, people with walking aids aren't really even disabled. However, the looks, comments and gestures of people would say differently. My grandpa used to get so angry with people that would help him. All he needed was a cane because he had a bad knee, and could not put much weight on it. Being in public with him, almost every time someone would open a door, or even try to help him with a cart. I felt his frustration because if he had only had a cane, and people would treat him with such generosity for something being wrong, others with more severe disabilities must get judged on this level much more harshly. Although people are trying to be nice, most of us do not realize that even though someone is not normal, or living to their standards does not mean we have to look at them any differently than someone without anything that would clearly indicate something being wrong. .
There is hundreds of differently disabilities that are out there. Many could be as simple as a skin pigmentation problem, to a little more complicated such as down syndrome. Either way, people usually treat them as if they are an alien. They are always so secluded, or singled out. Once you step back to think if that was you, or if you have someone close to you that has a disability your whole reaction would change. There is no need for us to judge and treat others as if they don't belong here at all.