Estas kvar homoj - four people exist.
Jen kvar homoj - have a gander at these four people.
Ĉi tie estas kvar personoj - the location of the people is this location.
In 'proper' (or textbook) English, it should be: '...I, my husband,...'. But not many native speakers would actually say it that way. So, technically, it's not irregular, it's improper English.
the "ge-" prefix denotes "of both sexes", so "gefiloj" is "sons and daughers", or "children" (in the sense of offspring as opposed to children in the sense of young people, which is more likely to be "infanoj"). This sentence refers only to sons, so "filoj" is correct.