A few months ago, while I was preparing for the NA GR, I have read in A Sicilian Romance notes something about Elinor and Marianne in JA's S&S, and I would like to share it with you now:

'The contrast of two sisters, one full of trembling sensibility, the other more governed by claims of reason, is common to sentimental and Gothic fiction. The heroines of Sophia Lee's The Recess, Matilda and Elinor, are one such pair, as are the cousins, Julie and Claire, in Rousseau's Julie; ou, La Nouvelle Heloise (1761). Julie is a likely source for Julia's name as Radcliffe was an admirer of Rousseau, using Emile; or, De l'Education extensively for the alpine sections of The Romance of the Forest. It has often been suggested that Radcliffe's Sicilian sisters form a model for the Dashwood pair in Jane Austen's Sense and Sensibility, in which Marianne's excess of sensibility and Elinor's good sense are demonstrated by their separate devotion to the different arts of music and drawing.'

A Sicilian Romance:
Emilia, the elder...had a mild and sweet temper, united with a clear and comprehensive mind. Her younger sister, Julia, was of a more lively cast. An extreme sensibility subjected her to frequent uneasiness; her temper was warm, but generous; she was quickly irritated, and quickly appeased; and to a reproof, however gentle, she would often weep, but was never sullen. ... Emilia's taste led her to drawing, and she soon made rapid advances in that art. Julia was uncommonly susceptible of the charms of harmony. (Ch. 1)

Sense and Sensibility:
Elinor, this eldest daughter whose advice was so effectual, possessed a strength of understanding, and coolness of judgment.... She had an excellent heart; - her disposition was affectionate, and her feelings were strong; but she knew how to govern them.... Marianne...was sensible and clever; but eager in every thing; her sorrows, her joys, could have no moderation. She was generous, amiable, interesting: she was everythting but prudent. (Ch. 1)