I believe that when you're blessed enough to have a disabled child, that God knew exactly what he was doing when he gave that child to you because he knew that you could handle it. You may not think you can in the beginning, but..... you can.
And you do....
... and that no matter how long that child is on earth,
even when they no longer are children and
become young men & women needing guidance,
usually for the rest of their lives,
God will and does take tender care of them,
even if they don't understand who He is....
Then again.. maybe they DO understand who He is
and us 'normal' people can't comprehend how the could know
but believe me.... they know and most of them
walk in the light of His loving kindness
& teaches us all a lesson