I think this thread would be better suited in the cannabinoids forum, I'm sure a mod would move it for you. many od'ers have experience with synthetic noids, in fact possibly even more than the cannabis forum, but still I think you would get better responses there.
my take on it id that nothing that happens as a result of taking research chemicals would surprise me. I've seen people green out and even had a mini seizure myself from all natural cannabis when I was younger, so the potential side effects from full agonists are endless.
ninja edit: I think responsible store owners aren't selling this shit period. but herbal incense is more accessable to people under 18 than alcohol is to people under 21. there are specific laws to punish people who provide alcohol to minors, there are no specific laws that say herbal incense can only be sold to people over 18.
ninja edit 2: and to anyone wondering why she's using drugs in the first place, take a look at the people who raised her