The Blessed Mother of God when She detailed the way she wanted the Miraculous medal designed.
She held in Her hand a globe and used the word globe.
According to most of the the websites I've been viewing today, St. Catherine Laboure heard the words..."The golden ball you see represents the whole world, especially France, and each person in particular."
It was a golden ball that was seen, and most of the websites I looked today at used the word "ball," not "globe." You might not think that there's much of a difference. And maybe there isn't.
I have no idea what the original French word that would have been used. It would be interesting to know.
The private revelation of Catherine Laboure does led itself to the idea of a ball earth. But can one really make a specific determination of an important subject from one private revelation?