L-2 dependent status for a child continues until the child is no longer eligible as an unmarried child under twenty-one. Turning eighteen does not end it, but she is not employment-authorized at any age in that status.
Plan the transition before the age limit
Hypothetical example: A child in L-2 status may attend school, including university, and may remain until eligibility ends. What she cannot do is work, and that limitation applies whether she is sixteen or twenty. Families usually discover the practical consequence when a first job or a paid internship comes up, so it is worth explaining early. As the twenty-first birthday approaches, the family should decide in advance what her own basis for remaining will be, since options require preparation and some cannot be arranged quickly. If she plans to study, changing to a student classification while she is still in valid status is generally easier than reacting after eligibility has lapsed, and the school's designated official is part of that process.
The family file should separate the principal's assignment dates from each dependant's education and employment plans. Hypothetical example: A marine-navigation manufacturer sends a specialist to launch a U.S. support team while the spouse plans a career change. A spouse in qualifying L-2 status may work incident to status, but the new employer may need status evidence for its records. A child may study, yet age-out timing can require a separate plan before the family relocates.
Record intended travel separately for each dependant. A principal's urgent commissioning date need not force a child to move before the education plan is settled.