You pretty much mentioned all the things different people do. So which does she want to do? I don't flat much. Less than once a year. I carry a spare tube and CO2 inflator... sometimes.
What ever she or you decide is best, just make sure she practices doing whatever is required a few times. Especially if you use a CO2 inflator. Some don't do what's expected when you puncture the cartridge. And in the heat and rush of trying to get back on the road they can frustrate a person.
There is also tubeless that can be considered. I'm not there yet and maybe to old to learn that new trick.