The character of Emma is introduced in such a way that she might be considered a reluctant heroine. The narrator, who possesses Austen's ironic voice, says:
Emma Woodhouse, ... seemed to unite some of the best blessings of existence; .... and had, ... been mistress of his house from a very early period. ... Emma doing just what she liked ... . The real evils ... were the power of having rather too much her own way, and a disposition to think a little too well of herself;
Therefore, the conflicts Emma gets into come from "having too much her own way" and thinking "a little too well of herself."
Emma is devoted to her father and their caring but straight-talking neighbor Mr. Knightley. Her dearest friend is Miss Taylor who has just become Mrs. Weston and thus retreated from center stage to the wings of Emma's life. To replace her, Emma befriends Harriet, a young woman of modest intellect and position in the world whom Emma determines to raise in importance.
Emma does this by discouraging her from accepting a marriage proposal from the man of hopes, farmer Mr. Martin, and by encouraging her to focus on the imagined affections of a man who deems Harriet too far beneath him for notice, the clergyman Mr. Elton. When that scheme backfires, Emma is surprised to find that Harriet fancies herself in love with and loved by Mr. Knightley himself. This possibility sets Emma's heart aflame as she realizes it will break her heart if Mr. Knightley attaches himself to anyone.
Meanwhile, Frank Churchill and Jane Fairfax provide Emma with other projects as Emma seeks to avoid Jane's company--helped out by Jane's efforts to avoid Emma's company!--and seeks to ascertain just how deeply Frank loves her, as she must certainly refuse him, thus breaking his heart, as she is devoted to her father and refuses to even contemplate leaving him for a marriage and home elsewhere.
Things go from bad to worse for Emma after Mr. Elton's surprise proposal of marriage, which she earnestly rejected, sends him to Bath to bring back a bride in the person of Mrs. Elton who proceeds to brag and arrange outings to Mr. Knightley's strawberry patch and Box Hill. The strawberry patch and Box Hill are disasters for different reasons, one of which is that Emma and Frank offend both Jane and Miss Bates, so much so that Mr. Knightley chastises Emma on their behalf.
In the end, as things go spiraling from bad to worse, all discover that Jane and Frank are secretly engaged,
But it is even so. There has been a solemn engagement between them ever since October—formed at Weymouth, and kept a secret from every body.
and Harriet accepts Mr. Martin with Mr. Knightley's blessing and Emma accepts Mr. Knightley's bashful proposal of marriage and Mr. and Mrs. Elton ... well … remain the same.