She probably won't lay with the ball because of the bell. That kind of ball is usually usec for cats. Get her a bnall without any form of noise maker and play with her so she gets to see what it's for.
As for the treats business. It is actually fairly sound advice not to give treats etc. What they don't mean though is not to reward her. They mean not to supplement her food with tit-bits etc as these can become habit forming and lead to bad nutrition and obesity in extreme cases.
When she has been a good girl it is OK to give her a treat to reward her. That will help encourage her to continue the good behaviour. Some dogs do enjoy a piece of the kibble. It's us humans that think they must be bored
You could try other things like pieces of Schmacko - dogs love them. You could make your own liver cake - which almost all dogs will do anything for. You just need to watch that you don't over feed her by giving too many treats and then her normal amount of food.
hth