In the article, it's stated that calling what Mary had scarlet fever makes the most literary sense. However, the book I'm reading, "The Wilder Life," says that there were some things Laura didn't know from her childhood and were therefore inaccurate when she wrote them. I wonder if that was one of the things, or I wonder if it was one of the things she wrote that she knew were inaccurate. From "The Wilder Life" it seems there's a lot of both.