Responses
Yes, they adopted! It was already implied in chapter 108 of the main story, look at this, you can see a little girl sitting with her back turned
https://www.mangago.zone/read-manga/love_is_an_illusion/uu/br_chapter-160690/pg-30/
This must be an alternate world
Because Heesoo is a Beta he couldn't have a daughter!.... wait, right! I think they did adopt a daughter.
Problem solved let's keep going