I think those aren't her children, she's been married for 13 years and they look a bit older than that. I think the husband's first wife died when the boy was a baby and that's why his dad chose Cookie to marry into the family. In the ost, Adnan looked miserable at his own wedding with Cookie.
I'm not saying that it's okay to treat the children like that just because she didn't give birth to them. I just think she has a lot of anger and resentment after finding out that Adnan's "affair" was longer than their marriage and she's unknowingly turned into a third wheel.
Edit: So this is airing twice a week on Thursday and Friday.
I initially thought so too. But in the pecap her mother says that eveil mom when they have children will compromise or something so I am confused.

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