This article reminds us that sometimes things are truly beyond our control and no matter how hard we work, things will not always turn out as we wish.
Not every child, even neurotypical ones, have the same potential. Not every child 
has the potential to be a star basketball player and no matter how many times you run them around the court and coach them on making baskets, they may only be average at the game of basketball. Not every child has the potential to be a great painter and no matter how many art supplies/lessons you pay for, they will always only be average painters.
And so it is with a child diagnosed with autism. This does not mean that you should not do everything you can, because we can never know what the limits of someone’s potential is. But you also have cut yourself some slack. Even the concept of “the best you can” is really subjective. If you are a single mom with 3 kids, there is only so much that you can do. And “the best you can” will be different if you yourself have some type of disability. So does this make you any less dedicated to your child? Of course not! Hopefully we will all do “the best we can” for our children. They will reach their best potential, whatever that may be and we can accept it gracefully.