If women in Shakespeare's time had been given the same opportunities as men, they would have been good writers. The first and the most important reason, as Woolf says in her essay, they had no chance to get an education at that time. Parents preferred to educate the boys, not the girls, because they thought, that only men would be able to study well, get a job and make money. They thought like that, because nobody before could give chance to women. If in that time women had an opportunity to study at school, learn grammar and logic, I think at least one of them would have recewed good grades and of course would be a good writer. Also women who had the gift to write could have been writing great novels. For example Judith, Shakespeare's sister had, "the quickest fancy, a gift like her brother's for the tune of words. Like him she had a taste for the theater." She just did not have an opportunity to express the gift that had been given to her. People in 16th century did not think that women could do it as well as men, even write better than men, because women were more sensitive and could understand things better.
The second reason, is that women in the 16th century would have been writers, if they would have been married a little bit older than they were, because first of all they had to make a career. It meant graduating the school, after that University and geting a job. At that time it was impossible, because they married too young, had many children and usually they were not happy in marriage. Writers need inspiration to write, but if they do not like how they live, they can not write well. Most of the time Elizabethan women spent taking care of the children and doing something at home. I think that they didn't have enough time to do something else, for example, writing a novel.
The third reason, that if women in the 16th century would have been more persistent, they could be good writers, if they would try to write and show it, finally people probably would understand it.