"The whole point of the niqab is to prevent women from making friends with locals..." - skyofblue

If what you say is true, then the obvious, logical response is to respectfully engage with the woman in the niqab. Befriend her. Don't judge her by her appearance, but only by how she engages with you. Doing so defeats the restriction that you claim she lives under. 

Truth be told, you don't care about Muslim women being able to make friends in Canadian society. What you care about is inculcating your personal view of womanhood on Muslim women. Only then would you consider being befriending one, despite any other virtues she may have. Hopefully other feminists are more inclusive.