Even if you disregard bias in interviewing/accepting, or assume that it never happens, there are serious differences in the way schools treat students with families. Penn State is incredibly family-friendly (i.e. on campus housing, preference in 3rd year schedules, flexible scheduling for family planning/child care issues (including ease of semester/year off options for new parents), etc.. Oh, and a fabulous school district right down the street. I have heard similar comments from spouses at most of the Osteopathic schools, Iowa and Ann Arbor. Others may have discussed this on the Spouses/Partners forum....a search might be worthwhile.
By comparison, I've heard other nightmare scenarios where absolutely no support is given and students with children are made to feel, um, less than welcome, including pregnant students who feel forced to quit/transfer and absolutely no flexibility in scheduling. Not that I think "flexibility" should mean special treatment, but if you have to pick up your child at childcare by 6 pm, there is no reason a clinical diagnostic module has to be done from 6-7 pm. Get my drift?