Share ownership and permission to work are separate. If the spouse qualifies for L dependent status, employment can be authorized incident to valid status, supported by the appropriate spouse-specific I-94 evidence.
Evaluate the proposed ownership and activity separately
Explain whether the spouse would invest, direct operations or perform services, and obtain review before work starts. For children, derivative L eligibility concerns unmarried children under 21; it does not carry the employment authorization available to a qualifying spouse. Two questions are commonly merged here and should not be.
The first is status: whether the spouse and any unmarried child under 21 qualify as L dependants at all, which follows from the principal's classification and the family relationship. The second is activity: what each person would actually do in the United States. A qualifying L spouse's employment authorization is incident to valid status with the appropriate spouse-specific I-94 evidence, and it is a benefit of that status rather than a consequence of holding shares.
Transferring an interest in the company to a spouse therefore changes the corporate picture, sometimes in ways that complicate the ownership analysis for the principal, without changing what the spouse may do. Where a spouse intends to invest, direct operations or provide services to the United States entity, describe that activity plainly and have it reviewed before it starts.