Can a Canadian live in the US but work in Canada without permanent residency status?

I was born in BC and now lie in WA. Several of my family members have lived through this. The agents at the border crossing (pick any of the four in Whatcom county, I like the one in Lynden) are very helpful on her legal rights to stay, what paperwork she will need. To give you a heads up staying in the US as a "visitor" and commuting each way for work until the residency paperwork comes through doesn't work well in their scheme.