So lots of smart HS kids struggle in college. One problem I see in my area is the smart kids don’t have to do squat to do well in HS. So they don’t learn really good study habits. First semester college is a big wake up call.
So in addition to the extra help – office hours, tutoring, etc. see if they have a “how to succeed in college” course. It’s usually designed for kids on academic probation and will teach study habits, time management, etc. You’ll have to search for it – usually like an academic support department. We found all sorts of “secret” classes and study help. They even have classes you take concurrent with the typically hard classes (say math) which teaches them how to do it.