Please define “good college”. There are plenty of colleges in this country (and in CA) where ONE grade of C isn’t going to jettison your acceptance.
Since your daughter is a HS sophomore, I would urge you to help her create a well balanced list of colleges for applications. Colleges with a variety of selectivity.
Free advice…start with a couple of affordable sure things for admission and build your list up from there.
There are plenty of colleges that would welcome a student with one C grade.