Wow, did you know this about Mary, Mary Quite Contrary?
Oh we do love a traditional English Nursery Rhyme!
Mary, Mary, quite contrary,
How does your garden grow?
With silver bells and cockle shells,
And pretty maids all in a row.
Did you know, the original "Mary Mary Quite Contrary" was called "Mistress Mary Quite Contrary" published in "Tommy Thumb's Pretty Song Book" around 1744.
The exact origin is not recorded by the author, but there are two main theories as to who "Mary" was:
The first is Mary Tudor, Henry VII's daughter who later became Queen Mary I (known as "Bloody Mary").
"How does your garden grow?" could refer to her lack of heirs or to the common idea that England had become a Catholic "branch" of Spain or to a reference of the many executions that she ordered which would effectively grow the garden or "cemetery". "Quite contrary" is said to be a reference to her unsuccessful attempt to reverse England back to Catholicism with "silver bells" referring to the Catholic Church bells and "cockle shells" referring to the pilgrimage to Spain. The "pretty maids all in a row" is speculated to be a reference to the many executions she ordered as "Rows and rows" is said to refer to the executions of Protestants.
The second theory is that it refers to Mary Queen of Scots with "how does your garden grow?" referring to her reign over her realm and the "silver bells" representing the Catholic sanctus bells. Now "cockle shells" has been interpreted 2 ways: insinuating that her husband was not faithful to her or referring to the exotic foods she ate. The "pretty maids all in a row" refer to her ladies-in-waiting.
Personally, I prefer picturing the ladies in waiting version to the execution version every time! 
Happy singing! 