Riding by herself

[OakLeaf]

Get her a TracFone or something along those lines. You can buy a card with only thirty minutes on it or you can buy some twenty dollar TracFones that come with twenty minutes already on them.

I agree. Or at least one of those panic buttons that were discussed recently. Or you may be able to add a handset to your existing minute plan, and restrict hers to a limited number of phone numbers incoming and outgoing. Honestly, if I had to choose between my phone and my helmet, I'm not sure which one I'd rather be without. It's a vital safety tool IMO.

[SouthernBelle]

You know, I bet you can get walkie talkies that would cover that range. Esp if it's flat.

[DirtDiva]

I think you've done all that needs to be done (although I like the idea of taking her to choose something bright to wear). She's twelve and ought to be more than sensible and able enough to cope with a 5km ride between school and home. Surely this a much less scary thought than the fact she'll be driving in four years time...