Thank you very much for your answer but what about this: https://www.uscis.gov/green-card/green-card-processes-and-procedures/child-status-protection-act-cspa
here it is written they are included in CSPA!! Also, it is written in dv 2023 documentation that : "if you submit your DV entry before your unmarried child turns 21, and the child turns 21 before visa issuance, it is possible that he or she may be treated as though he or she were under 21 for visa processing purposes.: https://travel.state.gov/content/dam/visas/Diversity-Visa/DV-Instructions-Translations/DV-2023-Instructions-Translations/DV-2023-Instructions-English.pdf
so again I ask you according to your experience, are you sure that we should not continue his application as my mother's derivative???!!!