"Are Grandparents Giving Too Much?" // Grandmother walking with her granddaughter(Photo: Digital Vision\Getty Images)

It's long been a grandparent's job to spoil the grandkids. However, roughly 40 percent of grandparents say they're helping their children's families with everyday expenses, according to a recent AARP survey. How should you navigate this thorny issue? Family psychotherapist Fran Walfish, Psy.D., author of The Self-Aware Parent, offers her best practices.

1. The devil's in the details. "Too many families land in my office after such transactions have occurred," says Walfish. Everyone needs to be clear on the agreement beforehand.

2. Pay for a say? No way. Nana shouldn't use money as leverage to weigh in on your parenting decisions. "Grandparents got their chance to make parenting decisions with you."

3. Make a withdrawal, deposit appreciation. For grandparents, there's an almost instinctual need for the next generation to have it better than they did. "But they are not obligated to give." Show gratitude, and the best way to do that is by spending the money wisely.