Do not assume documents from an earlier assignment authorize a new move or new employment. Review their validity and the family’s present eligibility for the proposed transfer.
Check changes that occurred during the absence
A child’s age or marital status may now differ: L dependent children must be unmarried and under 21. A qualifying spouse’s work permission depends on valid L dependent status and appropriate spouse-specific I-94 evidence, not simply on retaining an old card or approval notice. The record that settles a dependant's eligibility is the current one, not the one issued for the earlier assignment.
An approval notice from a previous transfer describes a period that has ended, while a child's age today is a fact about today. Where a family previously moved together, the questions worth re-asking are narrow: has any child married or turned 21, does any family member now hold a different status, and has any document been superseded by later travel. What goes wrong is treating a folder of old paperwork as a starting position rather than as history.
Rebuild the household picture from current documents, then compare it with the earlier file only to see what changed. A qualifying spouse's permission to work depends on present valid status and the appropriate spouse-specific I-94 evidence, so an old card proves nothing about the new assignment.