Should I be worried that my child doesn't know what they want to major in?
No. Most students don’t know what they want to major in when they start college, and others change their mind at least once. At most colleges, students don’t have to choose a major until the end of their sophomore year.
That said, choosing a major earlier rather than later can help students graduate in four years, because they'll have more time to take the required courses—and that'll save them (and you) the cost of a fifth year of college.