I found it very unrealistic that Charlotte would tell the whole, scandalous story of Georgiana's kidnap to a woman she'd only just met and whose name she didn't know. Everyone involved who cared about Georgiana would be desperate to hush the matter up, because in those days it would have ruined her 'reputation' even though she didn't do anything worse than arrange a secret tryst that went wrong.
Nor would she have confessed her feelings for Sidney to a complete stranger.
Even in the present day, if you met a stranger at a party and opened with a polite line about it being nice to get away from the crowd, you'd be left open-mouthed if your remark was answered with a detailed account of someone's secret affair and kidnapping!
The Charlotte/Sidney romance has just turned into uninspired chick-lit plotting now. How many more times are we going to see them become closer, then have a misunderstanding, then get closer again?
And Charlotte's devastation at seeing Sidney talk to his rich, widowed ex was OTT - he'd be unlikely to ignore her, and it wasn't as if she walked in on them rolling around together on snake-patterned tiles!
Rooting for Esther and Babbington now - they're the only ones I care about.