For women, you can choose some short skirts at school. Tight skirts are actually very professional, and on the top, you can choose some other collocation, such as a fresh and simple white shirt, which will make you look refreshing, but not too mature.
With this combination, no one treats you as a student anymore. In addition to this collocation, wide-leg pants are also a kind of clothing that can be worn often in school. In fact, when you wear wide-leg pants, you should wear them with your coat. You will find that this will make your whole temperament more gentle, which is actually easy to distinguish from ordinary students.
When choosing wide-leg pants, you can try to choose some chiffon wide-leg pants, which is actually very helpful for personal temperament. For the upper body, you should choose some slightly sexy shirts, and don't choose a round neck shirt when choosing shirts, which will actually make you look boring.
Choose some V-neck shirts properly. A small suit will make you look more feminine, but it will not be particularly mature. All in all, this collocation is more appropriate.