I don't think they'll include this character but no guarantee. The drama is short at 30 eps and barely connected…
Because there was an engagement between the two families and FL was banished to the country so he married her sister. Are you watching the drama or asking for spoilers?
The author is known for writing strong female characters and recently her novels have been adapted into Cdramas.
They haven't been released yet. The Glory is "inspired" by one of her novels but they changed so many things that it's best to view it as a separate work.
I'm not a fan of her mother or the supposed "loving mother/daughter" relationship. As you watch more eps, you'll realise she had zero interest in her daughter. She's obsessed with revenge and has no issues dragging everyone down with her. Terrific acting by the actress though.