Yes. An L-2 spouse is employment-authorized incident to status and may work for any employer, including the transferring company's U.S. entity. She does not need a separate application before starting, though tax and payroll registration are ordinary employment matters.
The spouse can work, including in the family business
Spouses of L-1 principals hold work authorization by virtue of their status rather than by separate grant, and the admission record itself evidences it, so there is no waiting period between arrival and a first pay cheque. Nothing restricts the employer, which means the U.S. subsidiary may employ her in its office, on its books, at a market wage.
Two cautions follow. First, if she is on the U.S. payroll her role should be real and documented, because a family member on the payroll who cannot describe her duties weakens the picture of an organization the founder directs.
Second, her authorization is derivative: it ends when his status ends, so a plan that depends on her income should account for that. Children in L-2 status may study but not work, and lose the status at twenty-one or on marriage. Hypothetical example: a Hope precast-concrete company transfers its operations director, and her spouse will handle accounts payable for the U.S.
affiliate. The first review produces two separate files: her petition evidence and the spouse’s ordinary payroll documentation. The admission record settles whether the spouse has derivative status, but it does not prove that the payroll job is genuine.
A written job description, timesheets, and normal wage records prevent the arrangement from looking like a paper role created only for immigration. The household should also calendar the principal’s status end date before committing to a long lease.