How does Kitty describe Waddington's Manchu mistress?

Kitty describes Waddinton's mistress as being very elegant and traditionally dressed. She is struck by the thick make-up she wears along with her traditional head-dress and ornate Chinese clothing. Something about the demeanor and serenity of the woman also makes an impression on Kitty and she wonders what secret this woman knows that gives her such serenity.