Yes. L-2 spouses are employment-authorized incident to status. That is true for L-1B families as it is for L-1A families, and it does not depend on which employer the spouse chooses.
Status length is the constraint that catches families
The employment question is straightforward; the duration question is where L-1B families get caught. L-1B status has a five-year maximum, shorter than the seven years available in L-1A, and the family’s status is derivative of the principal’s. A plan that assumes a spouse will build a career in the United States, or that children will complete secondary school there, needs to be measured against that ceiling and against whatever route might follow. Children hold L-2 as dependants and may study, but age out at twenty-one, which can arrive before the principal’s maximum does. Deciding early what happens at the end of the assignment is more useful than discovering the limit in year four.
Hypothetical example: a commercial-refrigeration controls firm transfers its systems specialist while the family expects the older child to work after arrival. The first review separates the principal's L-1B evidence from the dependants' plans. A qualifying L-2 spouse may work based on status, but a dependent child cannot rely on that same basis for employment. Record each person's passport and age milestones, and ask schools or employers what documents they require. This turns a vague family assumption into a decision about whether the child needs an independent route, a study plan, or a delayed move. The five-year L-1B limit should also be visible in the household timeline.