Because the case was reopened on August 18, 2022, It seems NVC consider that your priority date be counted to be current on August 18, 2022. Thus, the child CSPA age = the child's age on August 18, 2022 - the I-130 pending days
= (27 years plus 310 days) - (5 years plus 67 days) = 22 years 243 days > 21 years old
So, the child is age-out, i.e. the child cannot immigrate into US togther with her mother as her mother's derivative.
If the case was reopened on 07/02/2018, then the child was qualifed for the immigration benefits to immigrate to US with her mother. So, the petitioner (your cousin's siblling who filed the I-130) had better discuss with the lawyer to see whether the lawyer can contact NVC to justify 07/02/2018 as the case reopened date.
