A spouse and unmarried children under 21 are included as derivatives and receive conditional permanent residence with the investor, with their conditions removed on the same later petition. Age is the risk, because a process running several years can carry a teenager past 21 before residence is granted.
The derivative clock runs while the petition sits
Derivative eligibility depends on the relationship and on the child being unmarried and under 21, and these processes are long enough that a child who plainly qualified when the file was opened may not when it is decided. Statutory provisions exist that can, in defined circumstances, subtract processing time from a child's age for this purpose, and whether they help a particular child is a calculation for counsel rather than an assumption. What a family can control is sequencing and record-keeping: knowing every child's exact age at each stage, avoiding unnecessary delay in filing, and being ready to prepare an independent route for an older child rather than discovering the need late.
Two further points differ from temporary categories. Conditional permanent residence permits work and study without a separate permission for the whole family. And the conditions attach to the derivatives as well, so their status depends on the outcome of the removal petition, which is a shared risk rather than the investor's alone.