I remember our relationship as having come naturally to me, so naturally. That picture of my sister and me as kids on our cover photo? I asked my mom about it later, and she said she thinks it was, in fact, posed...not by her, but by me! I hadn't known she was taking a picture, I just loved my sister's presence that much.
But I realize that there are environmental influences which helped me along that path. I didn't understand that until I started caring for children this past year. I learned this lesson with two boys I cared for who have a decent age gap between them. The younger one is autistic. The older one is not.
And they did not have that relationship that Caley and I had always had. Far from it. As a sibling myself, it made me really upset to see this, and I really had to wrack my brain, to see what my parents had done (and what Caley and I had done!) to make sure Caley and I got along.
Once I stopped to think about it, I realized there were two big factors that helped Caley and I be so close. For one, our parents rewarded me pretty intensely for being a good big sister. I got pretty constant praise for being a good sibling (to the point of going too far, because society started praising me simply because of our narrative about disability, but that's not the point of this post). For another, something my parents had nothing to do with, Caley was someone I could play with. She was my best playmate in the whole world, and so, of course, she was also my best friend.
So recently with the big brother, I tried these things. I started rewarding him for good big brotherly behavior (small amounts of candy on days when he's behaving really well) and taking him to contexts where he will be rewarded (like his brother's therapy, where he's allowed to go back with him, but only if he's a good helper for his brother). At first I was concerned about the candy, worrying that the big brother would learn to be good to his little brother only when bribes were present, but I no longer worry about that. Because the candy is just a bridge, an incentive to get him positively interacting with his brother, and he's actually learning from it and realizing that positive interactions are possible.
The other thing that made my sister and I close was (that parents can influence, that is) having Caley as a playmate, as I said. And this one seemed impossible for these two boys. Between age gap and autism, the little boy couldn't keep up with his big brother enough to participate in his games (although I tried helping him, it wasn't a long term solution, nor did it go particularly well). If I wanted them to play together, I had to teach the big brother how to play his little brother's games.
So next time I was in the car with both kids, and the little brother was scripting with me, I started teaching big brother how to script. And now big brother scripts with his little brother unprompted, and they both enjoy it! It's a way for positive interaction. Even if your child doesn't script, there are still ways to play. The point is, you may have to be the facilitator here, if they don't play already, and teach the neurotypical child how to play their autistic sibling's games. (Even if it's teaching the neurotypical sibling to interact by lining up their own set of toys.)
Another, of course, was finding new games that both kids could play - that were neither games specific to either child's desires. For us, that's been hide and go seek. (An episode of Peppa Pig, by the way, taught the little brother how to do this, more or less, although it's not exactly traditional hide and go seek.) And so now they have even more games to play together, and now that he sees his little brother can actually be fun, his big brother is starting to interact with the little brother more and come up with even MORE games!
Around this same time, by the way, I started having one on one chats using my website explaining autism for kids, with the big brother to teach him about what autism is. I don't know if that's contributed to the shift in their relationship, but on the off chance it might have (or in general), I would recommend making sure your child understands what autism is and how being autistic affects their sibling. I've been using the videos on this website, breaking them up into a video a day, with the big brother. Though he wasn't thrilled about being forced (yes, I did have to force him - I debated that, too, but I'm moving soon so the deadline for me to be able to teach him these things made me decide that I had to enforce learning), he really has learned a lot and grown a lot more understanding with his brother as a result. Just in case that is what did the trick, here's my website that I used for that:http://aseforkids.weebly.com/
The last thing that you can do is get your child a sibling penpal with another sibling of an autistic child. If you're interested/think they would be, of course. It's a good way to help the neurotypical sibling feel special, to learn from other siblings, and to feel less alone. (There's a program for autistic kids, too, if you think your autistic child would be interested/up for it.) Wait times for the program are longer than I'd like (they vary - for the sibling program I would need to wait a bit to find someone to pair with a child, for the autistic program I'm already actively looking for pairs right now), but it is free and I do offer it.
Hope this post helps all of you! Contribute your own advice and questions down in the comments!
[Photo is of Caley and me, appropriately, playing together. We're swinging in the back yard under our sycamore tree. My mouth is open (I think posing for the picture, but I might be screaming with joy) and Caley, in her little pig tails, is just smiling in contentment. I'd guess that Caley was about 4 or 5 and I was 7 or 8 in that picture - and having a great time!]