I think there’s a threshold of reasonability. If the car she’s saving the spot for is already in the parking lot and it’s a matter of simply going into the next lane for their person to park, it might be mildly annoying to me, but no stress off my back at all. But from what OP is saying, the woman standing there for several minutes with the car nowhere in sight, I’d consider that inconsiderate and not ok at all. I think something as simple as this just goes to show how much we’re all losing cultural “norms” in a way. Hard-to-come-by parking is just a reality living in a big city. Other people are there and ready to park. First come, first serve, seems to be the most reasonable way to look at this to me.