From the facts you provide: you do not ordinarily live in Canada, you do not work in Canada (you have not been in Canada at all) and you are considered resident alien of the US, this means you are a non-resident for Canada tax. You do not report any US source income in Canada on your wife's Canadian tax return because in Canada we do not file joint tax returns. Non-residents only report Canadian source income, such as your wife will do. She is not resident of Canada for the same facts as you but she earns Canadian income.
She files a non-resident Canadian tax return only reporting her Canadian income. She will select married status, enter 000-000-000 for her spouse SIN, and in the section where it asks for spouses income she reports your worldwide income converted to Canadian dollars, and she must NOT claim any spousal credits on her Canadian tax return (as you mention that you earned income in the US). The spousal income reported on her tax return is not there to be taxed but is more informational. I hope that makes sense.
