I saw an interesting article on WebMD about the February issue of Consumer Reports having the results of their survey of the Doctor/Patient relationship.  The number one complaint from patients was the time spent in the waiting room. 

24% stated they waited 30 minutes or longer. 

Now imagine that 30 minutes with your young child.  Imagine that 30 minutes with your sick young child.  Imagine that 30 minutes with your sick young child and your other two who are not sick (but INCREDIBLY BORED).  Imagine that 30 minutes with your sick young child, plus your other two, plus the other eight running around who belong to the other equally miserable parents.

You get the picture.  Ask your Doctor to invest in waiting room toys before you bill THEM for your therapy sessions.