Does it bother anyone else that Nanny is so ...

madam and sir was used then yes.usually now things are much less formal and one can call thier employers by their christian names unless its a royal household

Georgie

Well, even today in some countries the live-in nannys have a super-formal relationship to the people they work for, so it being like that in 1060s England, isn't that strange. Also consider that the Nanny was even an older generation than Joeys parents, so formal talk would be nothing but natural to her. The family is quite formal as well. Notice even from the first time Joeys parents talks to nanny they don't call her by name, they just call her "Nanny". This implies they don't give her any identity other than being a nanny - which again tells her to keep the distance. Even though Joeys father say she's family, she's not real family, she is a servant. A servant who's had that position ever since Joeys mother was a child - and she doesn't know any other way.

And about formality - calling her employers sir and madam is far less strange by todays standards than a boy calling his father sir, like Joey does.

**********
- Who's the lady with the log?
- We call her the Log Lady.

When I work for family I always call the heads of the family Mr. and Mrs.
It is a sign of respect and also I work for them, they aren't my friends even though they are very kind people.
It's an old fashioned notion but I stick by it and my employers seem to appreciate the courtesy.