How the roles change the list.
Police certificates start at 16, so a 16–17 year old carries an adult document load with a minor's consent paperwork.
Every applicant files their own DS-260 and pays their own $325 — infants included.
Sponsor items live on the petitioner card and are done once for the whole case.
Add a joint sponsor only if the petitioner's income misses the threshold. Their income is not added to the petitioner's — they must carry the whole household alone.