The COPR (if driving) or PR card once she has it (required for commercial travel) will gain her entry back into Canada.dangerJones said:Ok, good to know-- perhaps I should have mentioned that she's actually a Vietnamese citizen, not Singaporean. Would that change things, seeing as she'd normally require a visa to enter the States? Or is the COPR/PR card still enough for entry into the USA?
To enter the US she needs to meet any visa requirements separately (the PR is technically irrelevant, but it will allow her to apply for a US visa from Canada instead of her 'home' country and they will assess ties to Canada and likelihood to return to Canada vs. the States) so it's probably worth applying once you are in Canada.
If you've heard anything different, it's likely because Canada relaxes visa requirements for US Permanent Residents with a green card. The US does not have a mirror policy - the visa requirements remain intact regardless of Canadian PR status (ie, for the US, requirements are only based on country of citizenship not residency).