Then your girlfriend must go back to the airline responsible for the initial delay (WestJet?) and inform them that she was improperly "protected" following the late arrival of the first flight. That airline will need to re-issue the ticket so that it includes travel to her originally-ticketed final destination (Warsaw).

I believe that she might also be entitled to certain protections (and maybe even a cash payment) under Canada's Air Passenger Protection regulations. More info here:

https://otc-cta.gc.ca/eng/air-passen...ons-highlights