A couple of thoughts, not necessarily completely on-topic here, but related to photos above...

The mark on JonBenet's right cheek which has baffled us all so much: Could it possible be a bruise/abrasion from the tip of a pool cue?

From Wikipedia:
Leather tips of varying curvature and degrees of hardness are glued to (or in some cases screwed into) the ferrule. The de facto standard curvatures for a pool tip are dime- and nickel-radius, determined by shaping a tip so that when one puts a nickel or dime to it, they have the same curvature. The tip end of the cue will vary in diameter but is typically in the 9 to 14 millimeter range with 12–13 mm for pool cues, and 9–10 mm for Snooker cues being most common.
On another subject which I know absolutely nothing about (since I didn’t raise daughters): Could one of the hair ties in her hair have had some type of ornament that might have been broken off? I know that one of the ties is red/black/white, so I don’t think purple would be used in that combination. But do we know about the other one? Could it have been more like a barrette -- or even a barrette with the bow as a decoration rather than a functional part of what held the hair? If so, this might account for two mysteries -- one of which is the broken purple ornament that is mentioned in the search warrant inventories found near the body.