No man, losing your head is the worst thing to do.
Aiyah, call her bluff, tell her that if she's so fixed on taking
the 5 bucks, take the matter to the police and let them hear your
stories. Also add to her that there is a heavy penalty for making a
false report to the police... most likely she will give up and
return the 5 bucks liao.
If not she also has a very weak story, if you wanted to rob her,
you would have asked for more then 5 bucks and certainly not in
such an open area. Ask her if she thinks 5 bucks is really worth
all this trouble... but of course you do because it's YOUR
money.