How will my child recognize me when I cross over - he died thirty years ago when he was just five years old.

We are informed, directly from the afterlife, that there will not be a problem. First, the child would have been looked after by relatives or specialists from the afterlife and given all the love normally given to a child. The child would be given education as if he/she was on earth and brought to visit you. But just as important, it has to be remembered that we go out of our physical body when we sleep and visit our loved ones in the afterlife. So the parents could maintain a close relationship with the child until they cross over.

For more on children in the afterlife see:
The Children's Sphere in Steve Beckow's New Maps of Heaven.