Women's-specific cycling shoes are built on a last (the foot mold used to shape the shoe) that accounts for typical differences in female foot proportions—most notably a narrower heel, lower overall volume, and a differently shaped toe box. These aren't just cosmetic differences; they directly affect how securely the shoe holds your foot. Heel slip is one of the most common complaints women have with unisex or men's cycling shoes, and on a bike, a slipping heel means lost power and discomfort on long rides.
That said, not every woman's foot fits the women's last. If you have wider feet or higher volume, a unisex or men's shoe might actually feel better. The best approach is to try women's-specific models first, since they're designed around your general proportions, but don't rule out other options if the fit isn't right. Just remember to convert sizing—women's and men's scales differ, usually by about 1.5 sizes.