She smiled cartoonishly.

What a charming amusement for young people this is, Mr. Darcy! There is nothing like dancing after all. I consider it as one of the first refinements of polished society.

She held out her empty glass and it was adroitly whisked from her hand.

[…] and I noticed she was sitting on the bluestone wall kicking off her thongs and looking all smiley and girlie, which meant pretty much for certain she was talking to Carl, who makes her act all teenagey sometimes because she's in love.