The engineer already has a company lawyer, so write for the spouse
A new arrival with an offer letter usually arrives with corporate counsel attached, and everyone else in the household is unrepresented.
The employer's firm handles the petition. It handles nothing else. The spouse who wants to work, the parent hoping to visit for a birth, the child moving toward an age deadline, the naturalization that shows up years later: none of that belongs to anybody yet.
Those are winnable queries. People type them in plain words, not form numbers. Whether a spouse can work. How long a visiting parent can stay. What happens to a dependent when a job changes.
Build one page per household question rather than one page per form. State plainly whether you take the matter when another firm holds the underlying case, because that is usually the thing stopping the reader from picking up the phone.
Cross link those pages to a short piece about working alongside an employer's counsel. Readers wonder whether they are allowed to hire their own lawyer, and the firm that answers it first gets the call.