We have a few icons in the house that we have mounted on the wall low enough for the children to venerate. They are reachable to the 7 and 4 yr olds, but my 2 yr old can only reach them with his hand. Our 2 yr old has tried to "swing" one icon back and forth on the nail, but he only did this a couple of times. We have some icons on the wall also above the beds, and my 2 yr old can reach the ones above his crib with his hand but he knows how to venerate them has not attempted to handle them inappropriately. Otherwise, in our main prayer corner, we have a couple icons on stands that can easily be taken down and held for each child to venerate when we say our regular prayers as a family.