"There was certainly at this moment, in Elizabeth’s mind, a more gentle sensation towards [Mr. Darcy] than she had ever felt at the height of their acquaintance. The commendation bestowed on him by Mrs. Reynolds was of no trifling nature. What praise is more valuable than the praise of an intelligent servant?" -- Pride & Prejudice
Frank Churchill evidently brings several horses and at least one manservant on one of his visits to Highbury. After concluding his visit, Austen wrote: “The pleasantness of the morning had induced him to walk forward, and leave his horses to meet him by another road, a mile or two beyond Highbury.” His horses could hardly arrange to meet him by themselves, so there must be a groom looking after them. The horses are mentioned, the servant isn’t.
It would be easy to assume that Austen didn't focus on servants because either a) she wasn't interested in servants or b) her readers weren't interested in servants.
In her private life, Austen did mention the family servants in her letters; they were part of the household. When she visited her rich brother at his grand estate, she met and befriended her brother's governess. She left a gift of fifty pounds to her brother Henry's servant in her will.
What about (b)? Is it true that Austen's readers didn't want to hear about the servants?
Well, actually, servants made frequent appearances in literature and drama. Servants are essential as messengers and confidantes such as Juliet's Nurse. They also provide comic relief and sometimes function as a Greek chorus, commenting on the shortcomings of their masters and mistresses. Don Quixote is considered to be one of the earliest novels ever written, (though Spanish, it was well-known in England), and Sancho Panza is right there alongside the knight.
In Lover's Vows, the play that the young people plan to perform in Mansfield Park, Tom Bertram plays a comical butler who can't resist reciting poetry. When Elizabeth Inchbold translated the play from the German, she enlarged the butler's part. Laurence Stern's extremely popular novel, Tristram Shandy, features Susan the chambermaid and Corporal Trim, servant to Uncle Toby. Pamela: or Virtue Rewarded, which was a huge hit with the public, is about an ordinary servant girl who resists her master's advances. He ends up offering her marriage. Teague, "a blundering and bewildered, hard-drinking but loyal Irish footman... regularly featured in various literary formats well into the nineteenth century," according to scholar Patricia Godsave.
Servants weren't always stupid, they could be shrewd. There was nothing uncommon in portraying a servant as wiser and more ingenious than their master and mistress, especially in comic plays. The pretty, saucy, maidservant was a staple figure in plays and operettas, including Shakespeare and bawdy Restoration comedies. Lucy, a maidservant in the comic play The Country Wife has "extraordinary" agency: "she is indispensable to the love story, saves her mistress from a disastrous marriage... and acts as the deus ex machina that resolves all the problems at the end of the play."*
In Austen, servants serve the mechanics of the plot just as their real-life counterparts served their masters and mistresses.
Fanny Price is "greatly surprised" when, after a long delay, a servant brings in the tea things at her parents house. She had assumed the "trollopy-looking maidservant" who answered the door must surely be the subordinate servant in this two-servant household, but the girl with the tea-tray looks even worse than the first one. Austen illustrates the poverty and mismanagement in the Price household and Fanny's sinking feelings upon realizing it.
Note that Austen's narrative voice does not extend any sympathy to these two servants, apart from mentioning that their mistress does not know how to manage them properly. Mrs Price is "dissatisfied with her servants, without skill to make them better, and whether helping, or reprimanding, or indulging them, without any power of engaging their respect."
She boasts of her "triumph" over the carpenter's ten-year-old son when she suspects him of trying to get a free meal in the servant's hall. Mrs. Norris's hypocrisy -- for she takes everything she can from the Bertrams -- is on full display here. The fact is though, that she knows the name of the carpenter's son, and his age, and undoubtedly Lady Bertram doesn't have the slightest idea who Dick Jackson is.
In Austen's world, people who talk a lot about servants or with servants are petty-minded and vulgar.
Mistreatment of servants is one of the way Austen illustrates bad character. The worst employer in Austen is General Tilney, who berates a servant for not announcing Catherine Morland before she enters the room. Catherine assures him that it was all her fault --she rushed in without waiting to be announced,
"[a]nd if Catherine had not most warmly asserted his innocence, it seemed likely that William would lose the favour of his master forever, if not his place, by her rapidity."
In contrast, Sir Thomas is extremely displeased by the fact that his son Tom has ordered the estate carpenter to build a stage in the billiard-room in his absence, but none of his ire falls on the servant: "It appears a neat job, however, as far as I could judge by candlelight, and does my friend Christopher Jackson credit.”
The way characters talk about and interact with servants reveal their good and bad qualities, but these vignettes are not an obvious commentary on the unfairness of the social order. The gardener who gives Mrs. Norris a lovely specimen of heath -- we don't know if he really agreed with her diagnosis of his grandson's illness. We don't know if the grandson got better. The story moves on. It wasn't about the gardener, it was about Mrs. Norris.
"Austen’s monsters are invariably attentive to the lower orders, for thus they exercise their self-importance." -- John Mullan, What Matters in Jane Austen
"[Baddeley the butler] said, “Sir Thomas wishes to speak with you, ma'am, in his own room.” Then it occurred to [Fanny] what might be going on; a suspicion rushed over her mind which drove the colour from her cheeks; but instantly rising, she was preparing to obey, when Mrs. Norris called out, “Stay, stay, Fanny! what are you about? where are you going? don't be in such a hurry. Depend upon it, it is not you who are wanted; depend upon it, it is me” (looking at the butler); “but you are so very eager to put yourself forward. What should Sir Thomas want you for? It is me, Baddeley, you mean; I am coming this moment. You mean me, Baddeley, I am sure; Sir Thomas wants me, not Miss Price.”
But Baddeley was stout. “No, ma'am, it is Miss Price; I am certain of its being Miss Price.” And there was a half-smile with the words, which meant, “I do not think you would answer the purpose at all.”
Mrs. Norris, much discontented, was obliged to compose herself to work again..."
* Godsave, Patricia A., "The Roles of Servant Characters in Restoration Comedy, 1660 - 1685." Dissertation, Georgia State University, 2018.