I would assume the seer was a globe earth believer because she was indoctrinated that way from birth, as are all modern era people, since the 17th century forward. I highly doubt the seer would have made the distinction between the globus crucifer she was shown in the apparition and the globe earth of her school days.
Maybe that means St. Catharine Labouré is now in Hell for believing in a globe Earth and delusions that the Mother of God told her the globe represents the world (which does not necessarily mean the Earth?) And especially France. Maybe all the conversions and miracles were phoney and the histories forged by those diabolical Jesuits?
Who knows, maybe all private revelations are people who unknowingly had something other then Kool-Aid in their water?
By the way, I've worn the Miraculous Medal for years so that I can't even remember when I first put it on. So, yes, I am more inclined to Mrs. Myrna's side on this particular subject.