"They are going home."
Translation:One idą do domu.
You're close. "Oni" means, that in the group there is at least one male human being. "One", for everything else. It shows that there is no male human being in the group.
Theoretically "one" could denote not only women/girls, but also boxes, cats or trees. In fact, it is really rarely used to denote something else than people (you just specify the subject, usually), so it's safe assume that's a group of women-only.
Hello there! A "chodzic" vs. "isc" question: I grew up speaking Polish and also took a few semesters in college. I recall "chodzic" being used in instances like "I am going home" because it was an action that was done frequently (i.e. a daily commute) — does anyone know if this is an accurate impression? I saw some chodzic vs isc discussion below but I'm still unclear on when it's appropriate to use either.