It seems we've come to what I call the "English literature exam question" problem. For example, a question in an English exam will quite commonly start along these lines...

"What did Shakespear mean when Mark Anthony declares "There is beggery in the love that can be reckoned...." ?"

I always had a problem with these questions, because there is no real way I can find out what Shakespeare meant by anything he wrote. He's been dead 400 years.

I can make a lot of educated guesses, but when you get to the nitty gritty, no one will ever know what he meant for sure.

Similarly, regardless of any evidence for or against "Ring a ring o' roses" being linked to the "Great plague" we will never be able to nail down when the rhyme even appeared let alone if it was actually connected to any event in history.

I say, either keep an open mind or agree to differ. We can't do much about it either way. : )

TTFN M'Lady P.