I for one thinks about Da Kyung in a different way. She is Pitiful and I feel Sorry for her.
What I wanted to say is that whatever she has done is not the right thing, however, I could understand her.
Also, the people who are blaming her for being in a relationship with a married man, it is simply not her fault. It was solely Tae Oh's fault. He is the one who is married and he has to protect the marriage. In the First few episodes he tries to have both of them by lying to her that he is Sick of Sun Woo, He only loves her and will get a divorce.
Also, to the people bad mouthing her because she tried to take the Son away from Sun Woo, it was her desperate attempt to keep the marriage in tact. That was what all the wives has done in this drama. Also, in her point of view, Sun Woo tried to get a Divorce by making Tae Oh an Assaulter, humiliated her and her family, made her to leave the town,etc. In her point of view, Sun Woo is not normal. So, Maybe, Whatever she was doing was also for the peace of mind of Tae Oh.
Also, if you have noticed during the last few episodes, all that they talk about is about Tae Oh's son. Which, thinking from her point of view is actually heartbreaking.
She despite being young and with no experience is trying to raise a Teenager with problems just for the sake of keeping her marriage in tact is a really hard task. And I personally think that she must be appreciated for her effort.