Well, that would be to prove a immigration status, so you'll need to show your child's current U.S immigration document.
Are you going to prove your child's immigration status?
Yes, i want to do it.
Good, then you need to have Form I-551 or Lawful Permanent Resident Card or Form I-766 EAD work permit.
And what happens if my child doesn't have permission to work? what to do then?
If that's the case, then the child may apply for a SSN if a federal or local law requires for him / her to provide a SSN.
And if my child is a Student elegible to work?
If he/she falls into a F-1 student status, the child must provide a letter form his/her school official identifying him/her and confirming its school status.
What if i don't hapend to have any documents?
Then you can provide us other documents we ask you, of course they mus t be valid.
And if the student goes for an CPT?