But as Wollstonecraft points out again and again, Reason doesn't have a gender. When you're right, you're right. As she says at the beginning of the book, "In the present state of society it appears necessary to go back to first principles in search of the most simple truths, and to dispute with some prevailing prejudice every inch of ground" (1.1).
Her style of writing pretty much follows this same pattern for the rest of the book. She constantly lays out basic principles, and then uses them as a foundation for building larger observations about society. It's a testament to how, when educated in the same manner as men, women are fully able to build solid arguments based on reason and logic. Wollstonecraft is super-smart, and knows that the writing style of A Vindication of the Rights of Woman is its own best vindication for, well, the rights of women.