The investor's spouse and unmarried children under twenty-one may be included as derivatives. A child who reaches twenty-one may lose derivative eligibility, subject to the age calculation rules that can preserve it in some circumstances.
Put every child's birthday on the project timeline
Hypothetical example: the couple have a nineteen-year-old and a twenty-two-year-old. The younger one may be included as a derivative; the older one cannot be, and would need an independent route. For the nineteen-year-old, the multi-year length of an EB-5 case makes the age question real rather than theoretical, and there are statutory provisions that can affect how age is calculated for these purposes, which should be assessed on the specific dates rather than assumed.
Marriage before permanent residence is granted also ends derivative eligibility for a child. During the two years of conditional residence the family members hold that status and its rights, and the conditions are removed on a later petition supported by evidence that the investment was sustained and the jobs created. Confirm each person's citizenship and current status separately, since those facts affect procedure.