I have a niece who is autistic and it took some time but we too, found her talents.
I worked in a production plant with an autistic woman and it was a pleasure, she never turned out a bad part, she never was late/or missed work, she was an asset to the company. It was a pilot program, and it was turning into a very sucessful employment situation. I have been to several workshops where adults with different types of mental issues worked and they turned out beautiful crafts and other items that were sold to the public. There are two shops here that are very profitable with the wood cabinents made and sold by these individuals. I have seen so many changes since the early 70's when I first started volunteering, and most all for the better! Thankfully over the last 2 decades the realization of what these children and adults can do is moving forward. As you stated, it just takes some time to investigate their unique individual talent and let them explore and perfect it!
There is nothing like the look on their face when they realize that there is something that they can do, enjoy doing, are good at, and the praise that goes along with it gives them the confidence to continue and try new things too :)
A big thank you to all who have given their time to help, teach and just spend time with anyone who is just a little "different" in their own unique way :D :D :D