This long form essay is of critical importance when understanding the origins of feminism and the various other women's movements like it. Woolf's argument is simply that she feels less empowered, less enabled, and less encouraged in her artistic process, because when she tries to draw from her artistic heritage, there are few female voices to help her capture the nuances of woman's issues.
In other words, there is a kind of mechanism that Woolf notices. She sees that what a child reads, that determines the future of their style. Humans are impressionable, so if someone sees that their point of view is not represented in any art or literature, then perhaps, that person may not feel brave in their own artistic life. That makes the problem worse, because people are more likely to write books that are like the books that they have read.
But in this desert of influence, Woman's voice is not completely absent in Woolf's academic upbringing. She says that George Eliot, Emily Bronte, and Jane Austen were female writers who helped her to understand her own calling to literature. Of those, she highly commends Jane Austen, because Austen wrote in an undeniably feminine style, much to the dismay of some people, but overall, she was successful, because she was an expert and a genius.
To Woolf, it is of critical importance that women celebrate their artistic talents, because even though a person's call to make art might look unlike anyone before them, Woolf reminds her reader that Austen helped her to feel like she could be true to herself, but only because Jane Austen took the time to make excellent, masterful works of art that were disciplined, but true to her experience of life.