To The Times
“The naming of grandmothers as “nanny” has little to do with goats, but is a hypocoristic form found throughout the Indo-European language family, in use thousands of years ago before the language groups split. It was found, for example, in the Indian word ‘nani’ (grandmother) and the ancient Greek word ‘nanna’ (aunt). The Indo-European hypocoristic principle (one syllable plus doubled consonant plus open vowel) is still alive and well today (in “doggy”, “Tommy” and so on). “Nanny” from Ann as a pet-name for a female goat, is first recorded in 1788 (OED) and Billy, for a male, in 1861”. (Letter written by Patrick Martin, Winchester, Hampshire, UK)
My wife is called “Nana” by the grandchildren. They have no idea that Nana goes back thousands of years. Whoops! The word, I mean.