WRT Charlotte/the Reptons - Lord Repton seems to indicate that Charlotte was livelier than he is finding Lucy to be, and she (Charlotte) definitely seems pragmatic - my guess is that her encounter with them wasn't as brutal as Lucy's was, because she wasn't as reluctant and reserved as Lucy is.

I agree with this - remember earlier in the episode when when was being shitty to Fanny and claimed to be joking, and Margaret had to chide her for needing to understand the fine line was between joking and being shitty? I think she knew that she needed to "perform" to his expectations, but didn't know when to stop.