I am a graduate student majoring in mathematics, and my major is "Application of Partial Differential Equations in Physics and Biology" in "Basic Mathematics". I know this question better, because when I was in college, I saw with my own eyes that most girls in my class were more diligent than boys, but frankly, their grades were not satisfactory. But most girls who study mathematics will choose to work in education when they graduate, so it is not difficult to talk about employment. However, as far as your question is concerned, what major should you take in the postgraduate entrance examination? Personally, I think, considering your situation and the situation of most girls who study mathematics, you should choose the direction of "applied mathematics" as your major, such as "information and computing science", which can directly inherit the undergraduate major, and choosing a refined research direction from it should still be promising.