Children do not receive employment authorization solely through L dependent status. A qualifying L spouse has a different status-based work benefit requiring appropriate evidence.
Review proposed activities separately
A family relationship to the specialist does not authorize project work, even if described as informal help. Identify the actual task and individual status before participation. The dependent framework generally covers a spouse and unmarried children under 21; each person must obtain and maintain the appropriate status.
The harder planning question is what the family does when the maximum is reached, because L-1B allows five years rather than the seven available in L-1A, and derivative status ends when the principal’s does. The principal’s L-1B case separately needs one continuous qualifying year abroad in the relevant three-year window, a qualifying related organization, and company-specific specialized knowledge required by the US assignment. Dependent child status ends at twenty-one, so a household relying on a teenager's help across a multi-year assignment should count those years before the transfer begins rather than after it. The practical advice is to treat the spouse's licensing as a parallel project with its own timeline, started as soon as the destination is known, rather than as something to look into after arrival.