Hugh Walpole 
The Duchess of Wrexe [EPUB ebook] 
Her Decline and Death: A Romantic Commentary

Superficially, this book is very similar to others of its type and time–a spirited girl comes out into society and must choose between her rebellious and outcast cousin or a conventional young man. Rachel chooses the conventional young man, but as their marriage begins to degenerate, she comes into contact with her cousin once more. She falls in love with him–will she leave her husband and run off with her romantic but weak lover? And looming over all of this is the spectre of her grandmother, The Duchess, an old woman whose powers and health are waning but not yet gone.