This "child" was 16 y.o. At this age we knew enough chemistry to laugh at people who made it to local news by blowing up their toilet with some creative mix of household cleaners instead of doing such things ourselves in school.

To put it simply - she must have been either malicious, irresponsible or dumb. Even considering her age - after all, in just two years she is supposed to be able to legally use cars, firearms and pretty much everything.