Nonsense. There is no natural rule that says that the polar vortex should stay in a regular pattern. It moves around just like the jet stream does (it is, in fact, a jet stream.) You have fallen for the media hype.
Perhaps, perhaps not, but apparently she may understand it better than you do. Your idea as to the normal behavior of the polar vortex is founded in myth.
The only areas of the Arctic that are open water this time of year are in the far North Atlantic and Bristol Bay. Neither of those areas are ever iced over until late in the freezing season even in a high ice coverage year.
Nothing weird about this:
Temperatures in the Midwest will rapidly rebound by this weekend with some cities experiencing highs that are 60-to-70 degrees warmer than their subzero lows Wednesday and Thursday morning.
Chicago, for example, could have a temperature rise of more than 65 degrees from Thursday morning to Saturday afternoon. That would be the largest temperature rise over 72-hour period on record in the Windy City, according to the Iowa Environmental Mesonet.