Typically undergrad b-schools require two math classes (including business calculus) and two semesters of statistics. In addition, in general the marketing field has become much more driven by data analytics in recent years.
I suggest the student review the curriculum at schools being considered.
One of my kids is very similar - doesn’t enjoy math and feels she’s not good at it. She struggled in high school somewhat with the pace of pre-calc and calc but got through them with Bs. Applied to schools mostly as a communications major. Found out she really doesn’t love her communications classes at all. Her favorite classes freshman year ended up being business calc and a data science class, where she earned As in both. Who knew?!