dbh - I know that Nanny is used in many families that's why I said it means something different to the royal family.

One of the most famous was Marion Crawford ("Crawfie") who was Nanny to our present Queen. She was considered to have been indiscreet in later life for revealing details (even very innocent ones) to various journals and continued to write articles after she left the family's employ to supplement her meagre pension and as a result was completely excommunicated from further contact, mainly on the orders of the Queen Mother. It was not yet the media age that we have now and obtrusiveness was more controllable.

Yes there could be ruthlessness and discretion is still expected from those who work for the royals at close quarters.