...the fact that when John and Isabella arrived for their visit, when Mr. Knightley came in he went first to Emma to make up their quarrel--before he even said hello to his brother.

And I loved how the two of them worked together to run interference in the conversation in order to steer Mr. Woodhouse and John out of dangerous conversational waters. When John gets upset about Mr. Perry (supposedly) offering opinions of taking the children to the seaside, Mr. Knightley is all ready with his plans for the footpath--and it's just the sort of conversational detour that Emma has been engineering all evening as well.