The facebook site for the Time Guardiansby Manfred Kielnhofer. They're Time Guardians - part of a series of statues. The adults were made similarly to the statues by Skulkalski. I'm not sure about the child statues, but it looks like he got one child to pose for him, then simply made multiple copies of the one model. Or maybe he used the same basic idea as Dead Girl. But they're certainly real, full size statues.
The second link shows a child-sized statue in a cross-legged pose, so I have no idea. Maybe he only did one layer with the child, then the rest were added later....?