There is a limit of 8 siblings and 8 additional household members that you can add in the application using the "Add Sibling" or "Add Household Member" links on your Household page. If you have more than 8 siblings, prioritize younger siblings who would be in your Primary or Non-Custodial Household(s), and leave out siblings in Independent/Other Households. If you have more than 8 additional household members to add, prioritize those in your Primary Household.
You should then use the additional information box on the Household Confirmation page to provide information about additional siblings or household members. Include the full name and age of each sibling/household member, and any other relevant context. Please confirm the correct Primary and Non-Custodial Household Size, taking into account any additional siblings or household members, as you will not be able to make manual edits.