[Fanny and Mrs. Ferrars] wanted to him to make a fine figure in the world in some manner or other. His mother wished to interest him in political concerns, to get him into parliament, or to see him connected with some of the great men of the day. Mrs. John Dashwood wished it likewise; but in the mean while, till one of these superior blessings could be attained, it would have quieted her ambition to see him driving a barouche. But Edward had no turn for great men or barouches. All his wishes centered in domestic comfort and the quiet of private life. (3.6)
Edward's dreams and hopes aren't terribly dramatic ones – rather, he just longs for a nice, normal, quiet life. While one might deride this for being unambitious and small-minded, one could alternately see it as a refreshing break from the pushy, social climbing ambition of his mom and sister.
Edward is very amiable, and I love him tenderly. But yet, he is not the kind of young man -- there is a something wanting, his figure is not striking -- it has none of that grace which I should expect in the man who could seriously attach my sister. His eyes want all that spirit, that fire, which at once announce virtue and intelligence. And besides all this, I am afraid, mama, he has no real taste. Music seems scarcely to attract him, and though he admires Elinor's drawings very much, it is not the admiration of a person who can understand their worth. It is evident, in spite of his frequent attention to her while she draws, that in fact he knows nothing of the matter. He admires as a lover, not as a connoisseur. To satisfy me, those characters must be united. I could not be happy with a man whose taste did not in every point coincide with my own. He must enter into all my feelings; the same books, the same music must charm us both. (3.11)
Marianne shows us her dreams for the future here – she clearly has a mystery man already composed in her mind, and is just waiting for him to show up in real life.
His person and air were equal to what her fancy had ever drawn for the hero of a favourite story; and in his carrying her into the house with so little previous formality, there was a rapidity of thought which particularly recommended the action to her. Every circumstance belonging to him was interesting. His name was good, his residence was in their favourite village, and she soon found out that of all manly dresses a shooting-jacket was the most becoming. Her imagination was busy, her reflections were pleasant, and the pain of a sprained ankle was disregarded. (9.11)
Marianne's imagination is so prepared for her dream lover to arrive that she seizes upon Willoughby instantly when he shows up – he seems like the right fit. She practically decides that she's in love with him before she even knows him at all.
"You have no ambition, I well know. Your wishes are all moderate."
"As moderate as those of the rest of the world, I believe. I wish, as well as everybody else, to be perfectly happy; but, like everybody else, it must be in my own way. Greatness will not make me so." (17.2)
Good old Edward. His sole ambition is to get out from under his family's pressure and make his own way – and in so doing, find his own particular kind of happiness.
There were moments in abundance, when, if not by the absence of her mother and sisters, at least by the nature of their employments, conversation was forbidden among them, and every effect of solitude was produced. Her mind was inevitably at liberty; her thoughts could not be chained elsewhere; and the past and the future, on a subject so interesting, must be before her, must force her attention, and engross her memory, her reflection, and her fancy. (19.7)
Even practical Elinor isn't immune to daydreams, and despite her greatest efforts to "chain" her mind to practical thoughts, she can't help but digress.
As these considerations occurred to her in painful succession, she wept for him more than for herself. Supported by the conviction of having done nothing to merit her present unhappiness, and consoled by the belief that Edward had done nothing to forfeit her esteem, she thought she could even now, under the first smart of the heavy blow, command herself enough to guard every suspicion of the truth from her mother and sisters. And so well was she able to answer her own expectations, that when she joined them at dinner only two hours after she had first suffered the extinction of all her dearest hopes, no one would have supposed from the appearance of the sisters, that Elinor was mourning in secret over obstacles which must divide her for ever from the object of her love, and that Marianne was internally dwelling on the perfections of a man, of whose whole heart she felt thoroughly possessed, and whom she expected to see in every carriage which drove near their house. (23.3)
Sigh. Again, we have to say it – poor Elinor! She's just had her hopes and dreams crushed, and now she has to reevaluate her whole future life. To make matters worse, she can't even tell anyone about it.
Elinor honoured [Marianne] for a plan which originated so nobly as this; though smiling to see the same eager fancy which had been leading her to the extreme of languid indolence and selfish repining, now at work in introducing excess into a scheme of such rational employment and virtuous self-control. (46.10)
Finally, Marianne has started adjusting her plans for the actual circumstances of real life – she decides to buckle down and be more like Elinor in her approach to the future.
Marianne Dashwood was born to an extraordinary fate. She was born to discover the falsehood of her own opinions, and to counteract, by her conduct, her most favourite maxims. She was born to overcome an affection formed so late in life as at seventeen, and with no sentiment superior to strong esteem and lively friendship, voluntarily to give her hand to another! -- and that other, a man who had suffered no less than herself under the event of a former attachment, -- whom, two years before, she had considered too old to be married, -- and who still sought the constitutional safeguard of a flannel waistcoat! (50.14)
This remarkable sentence sums up the whole of Marianne's development – from an idealistic, romantic, unrealistic young girl to a mature young woman, free of her childish prejudices. The outlook is good for this new Marianne.