Unless you are using a mealworm feeder and your parent birds use it regularly to feed their little ones you will rarely see the young after they fledge. There is another person here in Stafford that has photos of the families of blue birds that come back to his feeder for mealworms and water. The little ones are probably around but they are well hidden in the trees like Gin said. Look on the power lines early in the day if you have them near your house. I have seen several families of birds on the lines over the years. Don’t be surprised if you all of the young are not there. The young are very vulnerable to predators (hawks, kestrels, etc.) in their first few weeks out of the box.