It's a choice that can be made by applicant, if eligible.
What the Resident Since date on her GC?
If it is before May 8, 2020, she can apply today under General Provision.
General provision is generally easier: you don't need to reprove marriage, thus amount of evidence you need to provide is 80-90% less. US citizen spouse doesn't have go to interview, as oppose to 3 year rule where it's highly recommended. It's easier to adjudicate, there's fewer rules.
However, if she's only eligible for 3 year rule now, she can apply now. They way you described the trip, I doubt it would be an issue for marital union.