Treat the first year as provisional. Eligible spouses and unmarried children under 21 may seek L-2, and a spouse in valid L-2S status is employment authorized incident to status; children are not work authorized by L-2. Dependent periods relate to the principal's, so plan any renewals together.
Avoid commitments longer than the approval
Where the initial period is limited to one year, weigh leases, school enrolments and a spouse's employment against that horizon and against the possibility that the operation does not grow as planned. Ask what the household would do in either outcome before anyone resigns a position. Keep the family's documents accessible, and note that admission and permission to work are separate from any approval notice.
Add one further household exercise to that horizon: write down what the family does under each of the two outcomes, before either is in prospect. If the operation grows as planned, what changes about housing, schooling and a spouse's employment? If it does not, what does the household do, and by when must that decision be made in order to be orderly rather than abrupt?
Agreeing both while nothing is at stake is considerably easier than agreeing either under pressure. Hypothetical example: a courier network's transferee and family agree at the outset that a decision point sits three months before the initial period ends, and that a particular set of commitments will not be made until after it, which converts what would have been an anxious spring into a scheduled conversation.