Autism - get siblings involved

My son with autism has 3 sisters. D is 21, T is 18, and MH is 11. They all live at home with us, and sometimes (well, who am I kidding? Most of the time) the dynamics can be downright crazy. The 2 eldest bicker and in-fight alot, and the youngest is usually embarrassed by her older brother and his disability. The most I ever had hoped for was that somehow, magically, they would all love each other and show kindness toward one another, but I wasn't sure how to bring that about. I grew up the eldest of 3, with 2 younger brothers, and we all fought and bickered, but we were never given any guidance about our relationships by my parents. It was either "Get along, or else!!" or my mother would be sad that we were fighting. We grew apart as we got older, and only now as middle-aged adults with families of our own are we getting to know each other, and yes, I'm happy to report, really love each other. Wow, I want this for my kids! But I don't want them to have to wait until they are grown to be close to each other.
I want to say that what followed was my idea. That it was part of a brilliant plan I came up with, and that it solved the entire sibling issue. Well, I can't claim any of these things. But what did happen was practical, and subtle, and beautiful. Here's how it went:
D, who is the eldest, started doing JohnPaul's homework with him. She has been ill for several years now, and cannot work or attend college, so she's home when he gets off the bus. She started helping him with a few assignments, and then took over the homework job 3 weeks ago. In a few short weeks she has grasped his learning style, and works with him, modifying the work which allows him to do it as independently as possible. This means pointing to the words as he struggles to read directions and worksheets, rephrasing for him, and then writing the answers he generates down in large print on a wipeboard. He copies his own answers that she has written. She knows how to narrow down more complex assignments, giving him 2 choices instead of 5 or 6. His confidence has risen! He doesn't balk at homework time! And his sister has gained too. She asked me if I thought she would make a good teacher. I do, I told her. I am proud of them both. And this relationship has not gone unnoticed by the other 2 sisters. Now the 18 yr old is asking what can she do with her brother. The younger sister, aged 11, is losing the bossy tone, and has been more understanding when helping him with chores. I hear more "please set the table, JohnPaul" instead of "I said Set The Table!". Little changes are occurring, making me feel darn good. The 2 older sisters have taken it upon themselves to take their brother to the local library every week, guiding him to choose movies and books that are on his level. I haven't seen any change in their fiesty relationship yet, but at least they are both spending less time thinking about themselves and more time thinking about him.
That's what it's all about, I want to tell them. Thinking about others. I want to tell them this, even though I know they won't listen. The world tells us it's all about us. That we're #1. That success is the most important thing. Why should they listen to me? But I think one day, they will listen. They're already on the way to figuring it out for themselves.

And listening to what their hearts are telling them. It's all about what we can give to others.