[Nevadaref]

JR,
If the NFHS put out something on beads, then I missed it. If you find it, I would welcome seeing it.
You are probably right on this one. However, I do still have some question about how the beads are being used. Are they decorative or are they used to control the hair? Clearly head decorations are prohibited.
On the other hand, the NFHS just published a ruling on hair-control items.
To me this is a key part:

Further, a ribbon worn in addition to a hair-control device is considered to be a head decoration, and is prohibited (3-5-3e). If a ribbon is being worn as a hair-control device, it would be permitted provided it is not judged to be dangerous or inappropriate by the referee (3-5-1).

This seems to say that items worn "as a hair-control device" are legal unless the referee deems them dangerous/confusing/inappropriate under his 3-5-1 authority.

Now I will note that all the items listed by the NFHS are soft (rubber bands, scrunchies, pre wrap and narrow, multi-colored elastic bands) and that beads are presumably hard. That fact could well be enough to require a referee to judge beads to be dangerous and thus illegal.