The spouse of an E-2 investor is employment authorized incident to status and needs no separate permit. Children under twenty-one may live and study but never work, and because E-2 offers no direct path to permanent residence, a child who reaches twenty-one loses derivative status entirely.
The category that renews forever still ends for a nineteen-year-old
E-2 is unusual among these routes in that it can be extended indefinitely while the enterprise continues to qualify, which encourages families to treat it as settled. For children it is not. Derivative status depends on being unmarried and under twenty-one, and there is no conditional residence or immigrant petition running in the background to convert into something durable, because this category leads nowhere permanent on its own.
A child who arrives at fifteen and finishes high school in Vermont turns twenty-one in the middle of a degree with no status of their own. The options at that point are the ones any foreign national has: a student route requiring admission and funding, an employment category requiring an employer, or an immigrant petition begun years earlier. Families weighing E-2 against an immigrant route should put each child's twenty-first birthday on the same page as the business plan.