To begin with, here is the sketch of St Helens mentioned at the start of the diary. If you are reading on Kindle, you might like to print this out.
The following map shows the relative locations of the Queen’s residences of Osborne on the Isle of Wight and Balmoral in the Highlands of Scotland. Buckingham Palace is in London, and Windsor (not shown) is a little to the West of London.
Finally, a handy map of the Island including those places mentioned in the story.