TO BE HONEST, Neoma was willing to turn a blind eye if she saw Dilan Choi treating Lewis harshly because that was Lewis' wish.
She realized that she could protect Tteokbokki because he was her bodyguard. Hence, she had an "excuse" to protect her aside from the fact that she was a decent human being. However, that wasn't the same case for the others.
[Like Lewis said, they can't afford the consequences of fighting against their rich bullies. I can protect them when they're with me. But what happens after that?]
So, she decided to clench her fists and simply ignore the "mild" bullying.
However…
