This is a fairly long video (8:35), and the opening 5 minutes in her language (which, as someone on YouTube says, sounds like Sigur Rós) may fascinate you or weird you out, but hang on until 5:20 when she starts her translation. Another excerpt:
"Far from being purposeless, the way that I move is an ongoing response to what is going around me. Ironically, the way that I move when responding to everything around me is described as being in a world of my own. Whereas if I interact with a much more limited set of responses and only react to a much more limited part of my surroundings, people claim that I am opening up to true interaction with the world."
Her YouTube index of films is here. Her personal site is here.
This is a point where decades of chomskian linguistics research might be useful: if it's a genuine language it will have to reflect the universal grammar structure. When that has been identified start mapping it to a semantic representation.
If that's not possible it's not a language.
And from her blog:
I did that video “In My Language” that I posted recently. I’ve gotten some interesting responses.
Several people said their autistic children (and one non-autistic sibling) wanted to watch it over and over again. One of them had a son who never hums at all, but hummed the tune from the video all day after he watched it. Others hummed along too. The parents described their children’s reactions as interested, mesmerized, and transfixed.
This is a common reaction between autistic people, I’ve noticed. We do have ways of communicating with things around us that are mutually comprehensible for many of us (not all of us, and not all the same things are comprehensible, there seem to be groupings in that regard). Our interests and our reactions are not random, purposeless, or useless, and are certainly not ugly things to be hidden away or trained out of.