A few generations ago in the USA it was common for rather ordinary people to have part time or full time servants or "help".
When the USA was mostly rural, young rural people had the goal of getting married and having their own households on their own farms, and they needed money for that.
So boys and young men would work as farm hands for other farmers, hoping to save up enough money to buy their own farm someday. And girls and young women would work as domestic servants hoping to save up enough money to contribute to their eventual marriages.
Thus a large proportion of rural men worked as employees of other farmers for part of their lives, and a large proportion of rural women worked as domestic servants for part of their lives.
In the cities boys and young men worked for small or large businesses, often hoping to save up enough money to start their own businesses. Going through the census of Lancaster (city), Pennsylvania, for 1860, 1870, or 1880, I once found a household that - according to the census record - consisted only of children, with the head being a 12-year-old boy who worked in a factory. And girls and young women worked in whatever jobs were considered respectable enough, which often included being a servant.
Here is a picture of the Borden House in Fall River, Massachusetts.
As you can see it is a nice house, but some readers may live in better houses for all I know - I did for several years.
In 1892 the estate of Andrew Jackson Borden was valued at $300,000.00, the equivalent of $20,000,000.00 in 2020, enabling his 2 daughters to live off the estate after Lizzie was acquitted of murdering him.
So Mr. Borden lived frugally for a man of his wealth, but he did have one live in servant, Bridget Sullivan, and I would expect that most of his less wealthy neighbors also did.
I remember visiting my great grandmother in the 1950s and she had a woman companion or servant or nurse or something. When my grandparents lived in the house later they sometimes had a woman come in to do housework. I suspect that the back bedroom where I sometimes slept was designed to be a servant's bedroom.
My parents were not as well-to-do, but I dimly remember that about 1956 or so a woman came to the house every day, to do household chores I guess, so maybe we had a sort of a servant for a while, though I don't really remember.
So my impression is that wealthy, upper middle class, and even middle middle class, Americans commonly employed live-in or walk-in maids or housekeepers as late as the 1950s or 1960s.
The UK had a much stronger class system than the USA, and I expect that upper middle class and middle middle class people expected to be able to afford a servant or two. From what I have read, members of the lower class considered it a step up from their usual status to be a servant in large wealthy household.
I note that Diana, Princess of Wales (1961-1997), the daughter of an Earl, had a number of jobs as a young woman.
She took a series of low-paying jobs; she worked as a dance instructor for youth until a skiing accident caused her to miss three months of work. She then found employment as a playgroup pre-school assistant, did some cleaning work for her sister Sarah and several of her friends, and acted as a hostess at parties. She spent time working as a nanny for the Robertsons, an American family living in London, and worked as a nursery teacher's assistant at the Young England School in Pimlico.
And some of those jobs sound like they could be classified by some people as being sort of a servant.
As the lower economic classes got better off in Britain they became less and less willing to work as servants, and I expect that a smaller and smaller percentage of the population were servants or employed servants as time passed.
But I think that it was still common in the UK about 1960 or so for middle class households to have a full or part time maid or housekeeper.
It is possible that the struggling husband doesn't live on his earnings but on an inheritance which is large enough to get by on, and it is possible the wife has some money from her family.
And maybe the family manages their money foolishly and hires a maid/housekeeper they really can't afford, because when they grew up household servants were more common and affordable for middle class people.
Anyway, any users of the site who actually were middle class British back around 1960, instead of merely having watched a few British movies and TV shows from that era, might be able to give a more accurate description of how realistic the movie is.