strikerr welcome to the QR forum.

Since all five passengers are on the same reservation (PNR) but each with different ticket numbers you should be able to check them in at the OWE check-in desk together with yourself..

With regard to boarding I would say that it is not possible. Of course it depends upon those manning the gangway entrance. I have the feeling that letting non OWEs accompany you would dilute your personal, and other OWEs priority boarding privilege experience.