When S1 was at UChicago, we had to answer questions on a checklist about coverage levels provided for various things, but not the premium. Would be difficult to discern from premium amounts whether a parent has excellent coverage or not, since employer decisions about how much they pay vs. employee (and demographics for one’s family coverages under ACA plans) can vary hugely.
That said, when we applied for FA, we told them about my extremely high medical expenses in the hope of getting some sort of accommodation. At that point, they had our W-2s, which would have included the employer paid premium and a reasonably good estimate of employee premium (which was pretax, but was the sum of medical + dental + vision, as applicable).