You mentioned the bus in a couple comments - using the public school system’s buses doesn’t make them have to follow any particular laws that apply to public schools and not private schools. In PA, districts that provide their own students with transportation must also do so for students in charter and nonprofit non public schools in their area. Info on transportation specifically is here: https://www.education.pa.gov/Teachers%20-%20Administrators/Pupil%20Transportation/Pages/Pupil-Transportation-FAQs.aspx That doesn’t impact the classification of or requirements placed on the school being provided the transportation.