No problem. With her application, it shouldn't be a big deal either way. I get a little nervous when Nissan/Infiniti starts massively extending OCIs and "letting" people use conventional. The replacement for my G37 has a rather long OCI, and you know people will be using cheap oil in it, since it's allowed. That's not to say that can't work; one should just watch OCIs.
As a sidenote, in Canada, I don't think you'll easily find Nissan Motor Oil 0w-20 SN. Imperial Oil, our Exxon-Mobil, provides the service fill for Nissan/Infiniti dealers, with M1 being pushed.