That title is probably an oxymoron since Regency Ladies did not have careers. They did not toil or soil their hands or clothing. Today, a woman might be admired for her ability to cook a gourmet meal, in Regency times a lady did not cook and probably did not go into the kitchen. The cook would come to her to discuss the menu.
[As an aside, one interesting thing I did learn is that a cook was sort of like an independent contractor and worked out her own deal with the family for whom she was employed. She did not come under the authority of the housekeeper.]
But cooks and housekeepers were not ladies.
In actuality, a lady's primary goal in life was to marry and marry well. That was her career and rather than getting trained in a profession, she learned things like fine embroidery or music which were intended to make her more appealing to a potential husband.
The only acceptable careers for a lady, and this would only be in dire circumstances such as being an old maid or widow or orphan without any resources, were governess or lady's companion. These positions might hold slightly elevated status within the household, but they were still never the social equals of the family for whom they worked.
Another option, which wasn't really a job, would be to care for the children of a family member or be the companion for a widowed relative in exchange for room and board.
In any case, marriage was the best option available. For many women, marriage provided a bit of freedom. They generally had a household to run and a certain amount of pin money which was theirs to use. Rather than being subject to the authority of their parents and possibly older brothers or brothers in law, they were subject only to their husband's authority.
Although I am glad that women today have many more options, as a writer, the urgency of marriage during this period makes for some interesting plots. If a woman was unhappy or abused at home, it is not as though she could pack her bags, rent an apartment and seek her fortune. She had to find a man.
Today, if a woman found herself without money to support herself, she might go and find whatever work she could and people would admire her tenacity. In Regency times, going out and taking any job she could find would send a lady to the depths of the social dungeon and she would never recover.
Today, women often want to work in order to have security in case their marriage ends. During the Regency, women needed a marriage to secure their future.