Sorry to hear about your sister's injury and hope she heals quickly.
The Gunting is not a knife I leave lying about in spite of the fact that Java the Younger and Mrs Java have been shown and briefed on its potential for injuring "knife savvy" individuals. The G kin-op was not designed to be used on your leg or anything larger than your wrist for this very reason. In a clutch, if you get crowded by the BG you now know what some of the live G's capabilities are. Buy the Trainer! Watch the tapes! The drone is extremely effective as a trainer, you won't cut yourself (normally), and is almost as effective as personal protection without bringing deadly force into the equation. And as Bram says, "Never Assume."
Best to you and yours,
<b><font color="blue">"A hole-less knife is a soul-less knife is a whole less knife" <i>-Javanese proverb</i></font></b>