Documents she created inside the company: specifications, change logs, calibration procedures, internal training material and engineering-review records that carry her name and cannot be found outside the business.
Authorship is the strongest evidence available
A declaration that an employee is highly skilled proves nothing, because skill is what the industry has. The petition needs artefacts. A configuration library she maintains, with revision history showing her decisions, demonstrates custody of company knowledge. A calibration procedure the company treats as confidential, produced under cover of a non-disclosure request, demonstrates that the knowledge is not public. Engineering-review minutes recording that a design change followed her failure analysis demonstrate that the company relies on her judgement. Training material she wrote for new hires shows the knowledge is transferred through employment rather than acquired at school. Where a document is genuinely commercially sensitive, redact figures and file a short explanation rather than omitting it. Add a table that sets each company-specific item against the general industry equivalent so the distinction is visible at a glance.
Hypothetical example: a laboratory-automation company says its engineer knows a proprietary fault-detection routine, but the routine exists only in her memory. The first review should produce versioned technical records, examples of when the company used the routine and declarations from supervisors who can explain why competitors do not use it. Those artefacts settle the specialized-knowledge point more reliably than praise. Preserve confidential details under appropriate redactions, then connect each exhibit to a specific U.S. duty; a secret that the proposed job never uses is not a reason for transfer.