It depends when she is finishing work in uae and cancelling her status. If she exceeds one month grace after her company visa is cancelled, she will have to pay the fine per day.
You are planning to bring her in March, so better if she leaves work in February so she will have grace period until march.
its not necessary to come back to pakistan after uae visa is cancelled. She can travel to canada directly from uae.
But if she is planning to finish work now, then she has to return to pakistan and update her pakistan address with ircc or you have to bring her earlier than march and once she is with you in canada, you will update her canada address with ircc.
In any situation after her visa is cancelled in uae, you have to update ircc of her new address.
