Community Colleges offer online courses. Students can get dual credit -- high school credit while in high school then college credit after matriculation into a college. It is important that the credit be used as high school credit while in high school and NOT college credit. Otherwise a student enters college as a transfer student limiting admissions and financial aid options. Once a student has enrolled in college then s/he goes back to them and submits the transcripts for credit for the college courses.
With accelerated learners, if they can handle the content and can meet DEADLINES, then this is an excellent way to meet academic needs and save money on college. However, there are some caveats:
Students need to be able to meet online deadlines
Students need to be able to handle online discussions, posts, and interactions -- their classmates are college students and they will write things you may not approve of
Parents need to be aware that some straightforward courses can be taught in a controversial manner --- it is a thing these days
Students need to understand and parents need to supervise grades -- an "F" is a problem, it can even impact being able to attend some colleges later on
Attending community college is also an option but be aware that you student is on a college campus with adults, adult posters, adult discussions, and adult opportunities. I cannot stress enough how mindful you need to be about how controversial some subjects are approached these days. Navigating those waters might be tough for even you much less your child.
Finally, use ratemyprofessor.com to check on professors, content, and other students' experience. It won't tell you everything but you can pick up some insightful or helpful information before signing up for a class.