I Have a Child With Autism

I have a question to ask. Why are most autistic people left out on things? That's very sad. One of my cousins is autistic and she says she is left out a lot and she tries to get involved but our other cousins kept pushing her away or lying. I told them it isn't fair and stop being jerks to her. One said, "Didn't anybody teach you that life isn't always fair. We don't want her around because bluntly, she is different. Nobody wants to be hang with someone that is different. She gets called "SPECIAL" by the older adults. What's special about her. She ain't nothing special. She is not special. She needs to do the hard work like everyone else. You can hang with us, just ditch her." And they walked off. No I'm not ditching her.
Also are people with disabilities called "special"? I don't get it. Aren't we all special in our own ways?