The House of Windsor is the reigning royal house of the United Kingdom and the other Commonwealth realms. Queen Elizabeth II has just passed away leaving King Charles III in her place upon the throne.
I found this old pump in the gardens behind a museum in Winborne, and at first thought it might represent the Windsor family crest:

You can make out a ‘W’ and a regal lion and the year of 180? something. The Monarch on the throne from 1801-1809 was George III (George William Frederick). His family did have a lion in their crest but not a ‘W’. And he was not in the Windsor family.

Upon closer inspection, I can just make out an ‘E’ on the right side of the lion, which means the ‘W’ likely represents ‘West’ and the ‘E’ would be for ‘East’. So, although it is likely to be a Royal crest, or a lion to represent the Monarchy at least, the family in question would be Frederick.