If your citizenship application form included your children, they will also be invited to the ceremony and will become citizens when you do.
Children aged 16 years and over are legally required to attend their citizenship ceremony and take the citizenship pledge in order to become an Australian citizen. Children under the age of 16 are not legally required to attend the ceremony or take the citizenship pledge, however are welcome to attend the ceremony and are encouraged to take the citizenship pledge where possible.
Your invitation will advise how many guests you may invite due to space restrictions at venues.