The noun usherette designates a female usher in a cinema or theatre.

However, in the texts containing the first two occurrences of usherette that I have found, this noun designates a female attendant who shows people to their seats in a church.

The noun usherette is from:
– the noun usher,
– the suffix ‑ette, forming nouns denoting women or girls linked with, or carrying out a role indicated by, the first element, as in suffragette and munitionette.

Some of the texts containing the earliest occurrences of the noun usherette that I have found are interesting for what they reveal of crass misogyny on men’s part and aspirations to emancipation on women’s part—these texts are as follows, in chronological order:

1 & 2-: From transcripts of sermons delivered by the U.S. evangelist William Ashley Sunday (1862-1935):

1-: From the transcript of a sermon published in The Daily Journal (Freeport, Illinois, USA) of Monday 7^th May 1906 [Vol. 28, No. 53, page 4, column 5]:

We have had enough of listless, indifferent Christianity. We must be more democratic in our churches. There is too much cold formality. Many a man and a woman goes to church, longing for a smile, a hearty handshape [sic], or a kind word, only to be shoved into a back seat by some kid-gloved usherette.

2-: From the transcript of a sermon published in The Gibson Courier (Gibson City, Illinois, USA) of Friday 21^st June 1907 [Vol. 34, No. 35; Extra section: page 2, column 2]:

Once the Duke of Wellington went into a church to attend Easter worship and a poor man came and knelt beside him. The kid gloved usherette touched the poor man on the shoulder and said, “Not so close, my friend.” But the duke threw his arm around the man and said, “When we kneel before our God there are no dukes or kings or queens or earls; we are all saints or sinners.”

3-: From the Vicksburg Evening Post (Vicksburg, Mississippi, USA) of Monday 11^th November 1907 [Vol. 25, No. 270, page 6, column 4]—the German-born U.S. businessman, theatre impresario and composer Oscar Hammerstein (1846-1919) opened  the Manhattan Opera House, New York City, in 1906:

GIRLS ARE USHERS AT GRAND OPERA

New York, Nov. 11.—Tall girls, golden-haired girls; petite, piquant, brunette girls, graceful, softly treading girls—just wait until you see them at the Manhattan Opera House.
That doesn’t mean the ones on the stage. Nor does it mean the fair girls who will be in the audience. But it means a brand new sort of girls. It will be a sort of Manhattan Opera House pet squad.
Yes—a brand new sort of girl for America—a girl usher!
In trim black silk gown, with an Eton boy’s collar and a flowing tie and pretty white lace cuffs—she’s there, a dozen of her.
It can’t be called one of Hammerstein’s original ideas, though that little wonder worker certainly has rushes of them to the head. The girl usher is a feature in many theatres abroad. Paris knows them. So does Milan. And Rome.
For a week they drilled the pretty squad so that now they know just where every seat in the theater is located.
They can read a coupon in a flash. And perhaps there is a psychic wisdom in Hammerstein’s innovation. Hitherto countless chappies have been content with a ticket of admission that entitled them to stand in the rear and listen to the silvery music.
But now there’ll be many chappies buying seats for the privilege of passing the coupon into the dainty fingers of the dainty usherettes.
The management says that the usherettes acquired their knowledge of the art of getting people seated more rapidly than ever did the male novitiates in the science.
The great advantage which the girl squad is expected to yield over the brass buttoned youths is in attention to their wealthy and fashionable sisters of the audience.
Hitherto women attending the opera have usually divested themselves of their furs and wrips [sic] in a vestibule not always free from draughts. They have done this rather than trust furs and delicate garments to the rough, unknowing handling of the men ushers. The girl ushers will assist women in putting off their outer garments at their seats or in the aisle.
The usherettes will be in all parts of the house, but they do not oust the male ushers entirely. The proud position of head usher still strides in pants.

4-: From The Gazette Times (Pittsburgh, Pennsylvania, USA) of Sunday 17^th November 1907 [Vol. 122, No. 112; Fourth Section: page 2, columns 1, 2 & 3]:

Pittsburgh Girls Want to Be Ushers

The Pittsburgh girl is positively up to date. Accounts were published in the newspapers of the employment of female ushers in the Metropolitan Opera house in New York. The news had barely reached Pittsburgh when Manager Thomas F. Kirk, Jr., received the following letter in his mail. The letter was signed by six young women, whose names we withhold for obvious reasons, but the letter is given exactly as Manager Kirk received it:
Pittsburgh, Pa., November 9, 1907. We, the undersigned, herein submit a proposition which we trust will have your kind consideration. In Wednesday Morning’s paper, November 6^th, we noticed where “Usherettes” in one of the New York’s fashionable Theaters had had been voted a success. This Management claims that the girls acquired more rapidly than the Ushers. We presume this will be introduced into one of our Pittsburgh Theaters within the near future, as Pittsburgh is generally in a position to grasp the latest and most up-to-date attractions and in view of the fact that the Nixon produces performances by the most refined element in this city, we kindly ask to be considered applicants for the positions, should at any time your Management adopt “Usherettes.”
We, of course, in no way have the young men unwillingly give up their evening task, but in case changes are made frequently, we would ask that the management make known that the position [sic] secured by the newcomers are not permanent and in that way, the positions would be given up satisfactorily.
It was also mentioned that their wearing apparel was of the same kind, the girls being stylishly gowned in black silk costumes, white collars with black four-in-hand ties, which the management claims enlightened the minds of the Audience.
We particularly wish to state that we are all refined young ladies employed in a downtown office doing clerical work. Should this proposition be accepted, we wish to inform you that we have any number of young ladies who would be willing to act as Usherettes.
Trusting this will have your kind and immediate consideration and thanking you in advance for any favors that might be shown, we beg to remain,
Very respectfully,
Manager Kirk wrote a courteous note declining to consider the proposition at the present, but who knows but what the enterprise of the Pittsburgh girl may yet displace the young man who takes your check and shows you, usually, to the wrong seat in a theater.

The following humoristic text mentions the positive effect that the usherettes at Oscar Hammerstein’s Manhattan Opera House had on the audience—this text is a passage from a review of the season opening at the Manhattan Opera House, on Monday 4^th November 1907, by Edward W. Townsend, published in The Pittsburgh Post (Pittsburgh, Pennsylvania, USA) of Wednesday 6^th November 1907 [page 6, column 4]:

This is true, but it will not be believed. However, it is important that future historians may have every source of valuable information regarding astonishing phases of life in this century, so it is here set down.
An usher at the Manhattan Opera House last night politely declined a tip. This really shocking occurrence so upset the would-be tipper that he went out after the first act to tell about it at a place where he expected to meet a friend and was unable to return to the opera, so great was the crowd of excited people who begged him over and over to repeat the details of what all considered a marvel.
The man, it appears, gave his coupon to an usher, who speedily found his seat. He had his opera hat, stick, gloves and top coat to dispose of. The usher deftly, quietly, quickly helped him. That polite attention alone nearly caused him to fall in a fit. Then he offered the usher a tip, a half dollar, and the usher politely declined it. The man sank back with a moan of despair. He believed he had lost his mind and was seeing things. By the way, I have not explained that the usher was a woman.