North and South vs Shirley

I have been watching the adaptation of Gaskell's novel and found similarity of theme to Bronte's Shirley. The difference that I see is that North and South has an external thematic dialogue while Shirley's is more internal but the resemblance is remarkable.
I was wondering if somebody else had this feeling.

Chronology
Charlotte Bronte published Shirley in 1849. Gaskell met CB in 1850 and published North & South in 1855. And while the plight of the industrial worker, post the Luddite Revolt of 1811, is common to both novels, the treatment of the heroines, Caroline Helstone / Shirley Keeldar vs Margaret Hale, is distinctly different. Bronte's characterization emphasizes internal mental states while Gaskell describes the external leaving the inference of the characters motivations to the reader.
Thus it would appear that while Gaskell could have been influenced by Shirley, Bronte's work is more original, especially stylistically.