4th gen it girl

This refers to Wonyoung from IVE, Yuna from ITZY, Sullyoon from NMIXX, or Karina from AESPA
Every kpop generation lasts a few years, 4th gen is from 2018-2022 so 4th gen groups are groups that were made during 2018-2022
This is a term in kpop

Karina is THE 4th gen it girl