A spouse and unmarried children under twenty-one may be included as derivatives and receive conditional residence alongside the investor. Age is assessed under the applicable rules rather than simply on the calendar, and a child who no longer qualifies needs a separate route, so the ages of older children should be reviewed before filing.
The clock and the queue rarely run at the same speed
Derivative eligibility depends on being unmarried and under twenty-one, and the difficulty in an immigrant category is that considerable time can pass between filing and an available visa. The Child Status Protection Act addresses part of that gap for some applicants by allowing certain periods to be subtracted from a child's age, and whether it helps a particular family is a question for counsel rather than an assumption. What is certain is that the risk grows with delay, and that delay in this category is common.
Hypothetical example: an investor's daughter is nineteen when the petition is filed and the family expects to travel within a year; the priority date does not become available on schedule, and by the time it does the question is whether her age can be treated as frozen for part of the wait rather than whether she is still nineteen. Each child's age should be recorded at filing and revisited at every subsequent stage rather than assumed to be settled.