Supporting documents for every included person are filed with Form I-140G through the official portal after USCIS issues instructions, and further items may be requested later. In a corporate case that means the employee's spouse and child must supply personal records into a process the employer is administering, so agree in advance how those documents are collected and stored.
Give the family a direct channel
Routing a spouse's civil records and a child's identity documents through a line manager is uncomfortable and slow. Set up a direct channel between the family and whoever handles the submission — external counsel is often the cleaner option — and tell the employee plainly what the company will and will not see. Agree deadlines for each document, and track passport expiry dates for the child alongside the adults.
Add one governance decision alongside that channel: agree in advance what the company does with what it learns. A process of this kind surfaces personal history that an employer would not ordinarily see, about a spouse and a child as well as the employee, and a company that has not decided how such information is handled will decide it under pressure and probably badly. Set out who may see what, how long anything is retained, and what happens to it if the employee leaves.
Hypothetical example: an employer agrees that document collection sits entirely with external counsel and that only a completion status is reported internally, which keeps the arrangement workable regardless of what the records contain and spares a line manager a conversation nobody wants to have.