Hello, During the time I write this post there was no guide providing all SIX locations of kindergartener's during the Hide and Seek quest. I found only 4 locations on the net. So I feel obliged to post this help:
1. behind the basketball hoop (pole) in the KID's PARK. (near the quest starting point). 2. in the trees to the left of the garage of mr/mrs.Garrison and MR.SLAVE’s HOUSE just above the trash bin. 3. behind the lamp post outside (to the left of) the TOWER OF PEACE. Right to parking meter and post box. 4. behind the fence on the very left of the FARM. In the corner. Down from gray cow. 5. in the BANK. Behind the desk (only in the room) just up from where you entered. You can see his foot under the desk. 6. (a girl?) just right of the STARK's POND, but you have to take the upper path to the next screen on the right. The clearing where you found the bag of stuff. The kid is just in the bushes on the right. The lower path right from the pond would lead you to the Church. You can see it clearly on the map (the fork near the pond).
Quest Reward: You get 6 new friends on Facebook. Nice.