Where It All Goes Down
The setting of "The Rights of Women" is hard to nail down, because it's never actually described. The speaker jumps from one set of metaphors to another as she calls on women to rise up and fight for their rights. First women are putting on their metaphorical armor and picking up their metaphorical weapons, then they are monarchs, ruling over men and forcing men to bow down before them, and then women are sacred—almost like idols on pedestals to be worshipped.
You could imagine this poem being recited by one woman to another (or to a whole group of women) in a crowded market or in a middle-class parlor. Or maybe they're in an open field somewhere out of town, surrounded by cows in a pasture. You can imagine this poem taking place almost anywhere you like, so long as there are women present who are ready to imagine what their world would be like if they took over and ruled over men for a while.
The Big Picture
And what did that world really look like in Barbauld's day? Well, people were just beginning to talk seriously about women's rights, and Mary Wollstonecraft's famous A Vindication of the Rights of Woman really made a stir. Many people attacked Wollstonecraft for trying to stir up a female revolution of the kind that Barbauld describes in her poem. Others attacked Wollstonecraft on a personal level, since she was a liberal, free-thinking type of woman. She had a long-standing relationship with the political essayist William Godwin, and actually had a child with him without being married, which was quite the scandal. (Fun fact: that child grew up to be Mary Wollstonecraft Shelley, who wrote a little book called Frankenstein that you've probably heard of.) So, because Wollstonecraft made some unconventional choices in her personal life, some people wouldn't listen to anything she had to say, no matter how well-argued it was.
But some people got on board with Wollstonecraft right from the beginning—after all, her message wasn't that women should rule over men, but rather that women should have equal access to education. This sounds like a no-brainer to us, but in the late 1700s, most men and many women believed what they'd always been told: that women weren't naturally as capable or intelligent as men. Anna Barbauld could tell them otherwise—after all, she was as well educated as most men and certainly as capable—but she also believed that she was an exception. She also thought that men and women shouldn't fight about "equal rights"—she wanted everyone to get along.
So, as you can see, the political setting of this poem is complicated, to say the least. No wonder it's so hard to figure out what Anna Barbauld's real feelings on the subject really were.