Of course, the mistake she made was in keeping the ball(s). My preferred method is to jab a screwdriver into it and give it back, apologising for the “sharp object” it fell on when it landed in the yard. They soon learn.
(I haven’t really done this, except in the alternate universe in which I am a grumpy old man.)
Boing Boing article on an Elderly woman arrested for keeping a ball kicked into her yard.
