Edited to Simplify:
She is from small village NWT, and a Dene. She comes from a culture different from ours. I learnt some time ago that one must not talk to northern community First Nations people in the same abrupt manner as we talk to each other in a big city like Toronto, as our tone and body language can be interpreted as offensive and rude. It's no different than dealing with some Asian cultures like the Japanese or Thais where it is inappropriate when dealing with customers to raise one's voice or to use language that is overly aggressive or disrespectful.

My point here, is that the FA probably did not appreciate this person's background. Now, before anyone says, boohoo it's Canada and the FA shouldn't have to accommodate such things, please keep in mind that the destination was Yellowknife deep in First Nations territory/land and that their culture prevails. I believe that this is a misunderstanding caused in large part by not acting accordingly when dealing with a First Nation's person and expect that had a FA or GA with more experience of working flights into First Nation destinations been faced with this situation, we would not have had this result.
This pax most likely did not have much experience in the fast paced, "in your face" culture of the south, and the onus was on the customer facing person (the FA) to be prepared for that. Please take this into consideration before casting stones at the woman.