Feminism as a relevant movement was created by some middle and upper class women in the industrial era who wanted to do more than sit at home. In the past, they would have had a valuable social role at home, but economics was making them obsolete. They didn't like being powerless ornaments, which wasn't historically how things were for most of them, so a few of them started a movement. The lower class women already worked, and this happened without a fuss because the economy needed workers. The society accepted that middle and upper class women should be able to behave like lower class women after a bit because it helped the capitalist economy to have more workers, and it fit with the western platitudes about equal rights.
That is the most parsimonious explanation. There is no need to complicate things by trying to say that the work of scholars caused an economic transition, rather than admitting that the only reason the scholars and activists arose and had an audience is that they were speaking to the choir. Economic needs meant that women would shift to a more useful work force role. Some feminists helped us rebalance our social and moral 'speak' to rationalize it in the educated classes before it happened. In the lower classes, they didn't have to because people weren't inhibited by that stuff since they were just trying to survive.
If we still had an agrarian economy, it wouldn't matter one bit what scholars and activists said; women would remain in agrarian roles. If we still lived in a hunter-gatherer economy, women would have the role they are best suited to in that kind of economy, which is relatively more equal, and occasionally a bit better off. Scholars and activists reflect change; it makes no sense to think that they cause it. They are inside the system just as much as the next person, whatever they say.
They can perhaps catalyze what is already going to happen; society can stagnate in the old modes for a long time, and then scholars can help a rapid catching up, or scholars can 'push on the door' as it opens, but the actual opening of the door has nothing to do with them.
Given this view, why do we need to bend over backwards to make Jane Austen out to have been a feminist? There are authors who held feminist views throughout history; this doesn't mean it mattered to societal change. We would have had the women's movement in some form no matter what our intellectual history was. Just look at China. People adapt to reality, not vice versa.
In Austen's case, she was defending the existing order against the Jacobins. She was a conservative clergyman's daughter who happened not to have married. She was a good author, so feminist scholars have a strong incentive to make her out to be on their intellectual 'side'; unfortunately, she simply wasn't. She made a few observations that they take out of context and portray as representative of a philosophy. If she lived today, she might well have been a feminist. But she didn't, and she wasn't. It's as simple as that.
Feminists, philosophers, and other purveyors of ideas usually inflate their influence. They fail to see that ideas aren't accepted unless conditions make them useful. Conditions are dictated by many factors more important than ideas, such as technology, climate, and the nature of the economy.
Let us suppose that someday men become useless to society economically. They will lose nearly all influence in that case. Some philosopher will justify why this is a moral state of affairs, and people will adapt. Whatever IS is what is defended. The same was true in the past for women. It would never have changed because some people didn't like it.