thanks for bringing that up.
You find these sort of people everywhere, they not only in Qatar or the middle east.
Anyways, if i was in your shoes i would have said to this lady 'does islam say ok to what you did? and the obvious answer is NO, islam says No to stupid actions/ behaviours like that.

I'm a muslim and I apologise on behave of her.
But be sure not all Arabs/Muslims/ Qataris are like that OR behave in this way!

I'm a muslim living in Australia, I LOVE being here the rules are the rules and followed by everyone. But, guess what some Aussies are very rude to Muslims and refugees. So, what you see in qatar happens to them when they are in western society but in a different way sort of thing.
However, I say speak up when the jump up in the queue! Why let them get away with? Say islam says no to this (hopefully this gets them to think a bit more about their actions)