When did it become expected for those who have two pennies to rub together to spend them all spoiling children? Why were 'a couple of new books' not an entirely adequate gift? Why do the grandparents have to do something extravagant and over the top because they have a little money?

Two things here:

1. The letter writer will hopefully realize that what she's asking for in her letter is permission to raise her kids to be spoiled, selfish brats,

2. If the grandparents never spend another dime on the kids and never have any reason to spend any of it, they might will it to the non-demanding, non-selfish brats in the family.

Grow up.