Hayley Mills is 20 in this?
I was amazing that the young looking Hayley Mills was supposed to be of a marriagble age in this film, she looked too young for that given its made/set in 1966. So I thought I'd check her IMDB profile to see when she was born and how old she was when she made this great film.
Bugger me if she wasn't born in 1946, making her 20 years old when she filmed this. She looks about 13 or 14.