Posted by Robert Hill on October 29, 2009 at 22:28:32 user eclrh.
In Reply to: older or younger? posted by Peter d'Owdon on October 28, 2009 at 18:47:46:
oldest children would retain the title 'Miss or Master [surname]' while subsequent children were called 'Miss or Master [first name]'
My impression is that that convention only applied within the children of each sex. Thus the eldest or only daughter would be Miss Blackett even if she had older brothers.
The female half of the convention is constantly relevant in 19th century novels (and their film and TV versions). I'm not sure I'd noticed the male half before.
I'd guess that the Billies were just being less familiar about Molly than Jim because she was a girl and deserved a little bit more courtesy.