I've never thought about this exchange as Mrs. Bennet thinking Lizzy was flirting with Bingley. I've always thought that when she says, " "Lizzy," cried her mother, "remember where you are, and do not run on in the wild manner that you are suffered to do at home." ", she's referring to Lizzy basically talking back and coming up with her own ideas instead of blandly saying she agrees with whatever the man has just said! Her father (imo) encouraged her to have a brain and use it. I don't think Mrs. Bennet was very wild about that type of training!