ios calendar invitation from paperless post no option to invite others

When I receive an invitation from paperless post and I think also from evite and I add the invite to the calendar when I go to edit the invitation I don't have option to add another invitee. For instance, I get invitations from parents of kids for birthday parties... I accept the invitation and click to add it to my calendar but if I want to add my wife as invitee that option is not available when I go to edit the calendar item. Anyway around this other than creating my own calendar event for the event and not using the prefilled version that is automatic from paperless post or evite?