This grandparent gig has no rivals.    You listen to the infectious laugh of 14-month-old Vivian and say to yourself: “This is the purest, most joyful sound in the universe.’’ In the next moment, you wince as she jumps on your groin. It resembles an America’s Funniest Home Videos segment without being heavily edited … Continue reading Childproof your house, but never put away hugs, laughter