The classic book that is entirely about what happens when you wish: Five Children and It, by E. Nesbit, published 1902. Nesbit had a firm grasp on the main reasons children read, and each chapter explores what happens after certain wishes are fulfilled.
The moral of the story: Be careful what you wish for! Also, simply having your wishes come true doesn’t mean you’re going to be happy. Every outcome has unpredictable consequences. Other people are always caught in your life web — you can’t make a personal wish without it affecting your community.
Neil Gaiman has proposed a gender divide when it comes to wish fulfilment in stories.
Boys: Boys are bigger, stronger, faster, invisible, can fly.
Girls: Girls’ real lives are based on lies. Their parents are not their real parents — they are secret princesses. There’s a promise of transmutation.