I always thought it was Mrs Dashwood and Marianne who did not take to Edward right away, in contrast to Elinor. The narrator tells us that Edward "had been staying several weeks in the house before he engaged much of Mrs. Dashwood's attention" (my italics). By this point, though, Elinor can advise her mother that she will like him "when you know more of him," apparently having already learned directly that "his manners required intimacy to make them pleasing...but when his natural shyness was overcome, his behaviour gave every indication of an open, affectionate heart."

In discussing Edward with Marianne, Elinor reveals that they "have been at times thrown a good deal together," and that she has "seen a great deal of him, [has] studied his sentiments and heard his opinion on subjects of literature and taste," such that, by then, she knew him "so well" as to overcome the initial, "certainly not striking" impression of his manners, address, and person. These conversations always led me to believe that Elinor, less partial to flashiness and more discerning than her mother and sister, had indeed started to get to know Edward upon his arrival. If there is any indication that she did not, I missed it.