Page 332. " Elizabeth had mentioned her name to her mother, on her ladyship's entrance, though no request of introduction had been made. "
Lady Catherine
Public DomainLady Catherine - Credit: C. E. Brock

Although Lady Catherine is visiting Elizabeth in her mother's house, until the person higher in consequence (Lady C.) asks to be introduced, Elizabeth cannot make the introduction.

She has already bent the rules by mentioning Lady Catherine's name.

Page 333. " a prettyish kind of a little wilderness "

This isn't quite as insulting as it might sound. A wilderness, to Austen, was not an area of wild, untamed nature, but a deliberately-created sort of garden that was very fashionable at the time.