When submitting a new application, you must fill out one child form per child.  Individuals may add additional children/siblings to an application at any time by filling out the child form again.  Your queue on the application waitlist will be determined by the date in which the first child's application was originally submitted.  Any changes you make to your application while on the waitlist, including the addition of a child/sibling will not affect your spot in the waitlist queue.