Results of a search for “Eliza Haywood” in works 1700–1800 (excluding works by Haywood): 40 hits
Main references (30 = 75%)
In works by Alexander Pope: 19 refs = 47.5% (very prominent: 11 of the first 13 hits)
In works by Richard Savage: 7 refs = 17.5% (quite prominent: 7 of the central hits)
Reviews in The Monthly Review: 3 refs = 7.5% (prominent: 3 of the first 14 hits)
Fielding's Memoirs of Grub Street: 1 refs = 2.5%
Passing/incidental references (10 = 25%)
Walpole’s work on engravers: 2 refs = 5%
In the BM Cat. of MS: 2 refs = 5%
In bookseller’s catalogues: 6 refs = 15% (not very prominent, among the last hits)
Basically, Pope and Savage's bile (In The Dunciad, An Author to be Lett and The Authors of the Town) constitutes most of Haywood's reputation and representation in the 18th century. (If we add eighteenth century work first published in the nineteenth century, we can add Swift to this herd of swine [i.e., sexist pigs].) For a sample of the negative, dismissive, outrageous and idiotic statements made about Eliza Haywood in the last two centuries see my Wall of Shame (here).
Of course, if you look harder (under "Mrs Haywood" for example) you can find dissenting voices or, at least, other voices, which I will collect below …
. Charlotte Lennox, Henrietta, 2 vols. (London, 1758): 36:
"Well," said Mrs. Eccles, "how do you like my books? are they not prettily chosen?"
"I assure you," replied she, taking down one, "you chose very well when you chose this; for it is one of the most exquisite pieces of humour in our language."
"I knew you would approve of my taste," said Mrs. Eccles, "but what have you got?—O! the Adventures of Joseph Andrews—Yes; that is a very pretty book, to be sure!—but there is Mrs. Haywood's Novels, did you ever read them?—Oh! they are the finest love-sick, passionate stories; I assure you, you'll like them vastly: pray, take a volume of Haywood upon my recommendation."
"Excuse me," said Henrietta, "I am very well satisfied with what I have; I have read this book three times already, and yet I assure you, I shall begin it again with as much eagerness and delight as I did at first.
* * * * *
In the nineteenth century, the criticism is only slightly more varied, and that largely due to the increasing number of female writers and critics whose opinions were published.
. Anna Letitia Barbauld, “On the Origin and Progress of Novel Writing” (1810):
Mrs. Haywood was a very prolific genius: her earlier novels are in the style of Mrs. Behn's, and Pope has chastised her in his Dunciad without mercy or delicacy; but her later works are by no means void of merit. She wrote The Invisible Spy and Betsy Thoughtless, and was the author of the Female Spectator. But till the middle of the last century, theatrical productions and poetry made a far greater part of polite reading than novels, which had attained neither to elegance nor discrimination of character.
. Memoirs of the life of the Right Honourable Sir James Mackintosh, edited by Robert James Mackintosh (1835), 2.105 (22 June 1811):
Female genius always revives Mrs. Barbauld's generous mind. Her remarks on Mrs. Inchbald are excellent; what she says of Madame D'Arblay is excellent; and one sentence, contrasting the rapture of a first success with the languor and disappointment of more advanced years, is beautiful and affecting. Her own remarks are plain, short, and sensible, but have the painful appearance of flowing from a dispirited mind, and present a melancholy contrast with the works of her youth and enthusiasm. She informs me that Mrs. Haywood was the authoress of 'Betsy Thoughtless,' one of the favourites of my youth. She displeases me, by classing the 'Man of Feeling' with a book by Pratt, an imitator of Sterne ….
. Catherine Hutton, Oakwood Hall (1819), 93–94:
"How came this to find a place in your collection?"
"Indiana Danby! my dear," said Mrs. Oakwood, "is a novel of the middle ages. The shining light of the ancients, such as Richardson, Fielding, Smollett, and perhaps Mrs. Haywood, was set; and that of the moderns, such as Dr. Moore, Holcroft, Godwin, Miss Burney, and Miss Edgeworth, not yet risen."
. Charles Whitehead, Richard Savage: A Romance of Real Life (1844), ch. 15 fn.
Eliza Haywood, although now nearly forgotten, attained during her life-time to an enviable celebrity. Pope, in his Dunciad, has heaped terrible infamy upon her head. Her plays I have not seen; but I have looked into her novels of which "The History of Betsy Thoughtless " and "Jenny and Jemmy Jessamy " are the most considerable. They possess no common degree of merit, but are altogether unfit for modern perusal.
. Dr. John Doran, “Their Majesties' Servants”: Annals of the English Stage (1864), 1.344:
The "Fair Captive" was an adaptation by Mrs. Haywood, a lady who began by writing as loosely as Aphra Behn, concluded by writing as decorously as Mrs. Chapone, and left charge to her executors, in 1756, to give no aid to any biography of her that might be attempted, on the ground that the least said was the soonest mended.
So, Haywood was, according to her critics (on my Wall of Shame), a "disgraceful," "shameless," "vulgar" and "voluminous writer of indifferent novels" which detail "lascivious passion, rapes, adultery, and murder" and are, as a consequence, "altogether unfit for modern perusal" and "now nearly forgotten." Haywood herself "figures indecently" in the Dunciad—a phrase that elides Haywood's representation and her own putative indecency—and that "the least said" about her, the better.
Alternatively, we have (as here) "a very prolific genius" who "attained during her life-time to an enviable celebrity," and whose "works are by no means void of merit." Indeed, she is, "perhaps," one of the "shining light[s] of" eighteenth-century literature. Her "Betsy Thoughtless " and "Jenny and Jemmy Jessamy" are the most considerable" of her novels and the first of these was "one of the favourites of [the] youth" of Sir James Mackintosh.
Although it is possible to create the second, positive, picture from the evidence above, it is clear from my Wall of Shame and the full quotes above that such a positive portrait is not representative. It is necessary to largely ignore the qualifications offered, and much of the faint praise is offered in double-negative ("by no means void of merit") whereas the criticism is often unqualified and is stated positively.
[UPDATE 26 February 2015]