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Austen Sequels - Emma
By an Amazon.com customer
A Visit to Highbury/Another View of EmmaA Visit to Highbury/Another View of Emma by Joan Austen-Leigh
Buy used from: $6.35
Pretty decent view of Emma, through the eyes of a minor character.  Epistolary (in letters).
Later Days at HighburyLater Days at Highbury by Joan Austen-Leigh
Buy used from: $0.01
A continuation of the book above, for those who fell for Mrs Goddard.  Decent in its own right, but not really an Austen sequel.
Mrs. Goddard, mistress of a schoolMrs. Goddard, mistress of a school by Joan Austen-Leigh
Buy used from: $13.55
Looks interesting, but I have not read this work.  I wonder if it is a two-fer (of the books listed above).
Jane Fairfax: The Secret Story of the Second Heroine in Jane Austen's EmmaJane Fairfax: The Secret Story of the Second Heroine in Jane Austen's Emma by Joan Aiken
Buy new: $12.95 / Used from: $0.99
Not bad at all, but you are too much in Jane Fairfax's head.  Emma portrayed rather negatively. See my B-rated review
Perfect HappinessPerfect Happiness by Rachel Billington
Buy used from: $15.33
Hopes were raised high by one of the literary Pakenhams, but this was rated badly by critics.  I won't even bother!
Aunt CeliaAunt Celia by Jane Gillespie
Buy used from: $0.10
Rated badly at <http://www.pemberley.com/janeinfo/austseql.html>
Emma in LoveEmma in Love by Emma Tennant
Buy used from: $3.58
Avoid anything written by Emma Tennant, unless you just want anything Austen-related