SPOILERS AHEAD, READ AT YOUR OWN DISCRETION!
If you haven't played Mystic Messenger completely, you might read something that will reveal to you the complete story of the game. So please pay attention!
Carolyn is a musician. She is the ex-wife of Chairman Han and the biological mother of Jumin Han. She divorced Jumin's father when Jumin was 7 years old. As of Common Story/Deep Story, she is traveling around the world.
Appearance
Carolyn is a fairly tall, slender, pale-skinned woman. With short straight black hair that's tucked behind her ears, and grey slanted eyes.
She is seen wearing a long, tight, black dress, with a black leather belt around her waist. With a large indigo-blue overcoat that's made of a hefty material, and a purple scarf.
she's described by many to be extremely good-looking, attractive to many, including Chairman Han, whom she ended up marrying. She is also the one Jumin got his good looks from.
Personality
Carolyn is described as a cold, apathetic, self-absorbed, arrogant, controlling, and an extremely materialistic woman. She was shown to not value family nor love. Showing no significance to anything that wouldn't benefit her. Refusing to act like a mother to jumin unless he acts like something else to her, even asking for an enormous divorce settlement from Chairman Han. She was also shown to be overbearing around MC, whom she deemed as a person “beneath” her, and acting completely different when she thought MC was from a wealthy and powerful family, showcasing her greed. She also tried to bribe MC to leave Jumin, and tried to force Jumin to do as she says, displaying her controlling and domineering attitude.
She shows zero empathy to people around her, except people who will probably benefit her, making her insincere. Also apathetic towards her own family, cutting Jumin off after her divorce, only contacting him for selfish reasons, seeing value only in financial and social success.
She has no problem lying and manipulating others to get what she wants. Lying to Jumin about having brain cancer only to guilt-trip him into marrying the woman she chooses for him, not denying the fact that it's only to get some money out of the marriage, and not caring about how Jumin feels about the situation.
According to Jumin, she's competent, but a bit repulsing, as she can't keep anyone by her side. Saying that she “didn’t care about him, or how he was brought up, as she was busy living a life concerned with only herself”.
Relationships
Jumin Han
Carolyn is one of the main reasons Jumin is distrustful of women. According to him, their relationship is far from a normal mother-son relationship, describing her as cold, that he would do anything in his power to not turn out like her, even if he loses his money and honor doing so. She has little to no interest or care for her son, telling Jumin that conceiving him was not "magical" like how other mothers would describe it, that it was merely something she had to do, to produce the best CEO, with the best genes through a coordinated marriage, even using him to make deals with others that would only benefit her. Jumin also blames the way he turned out on his mother, saying that his therapist tells him to ignore her actions. She always told him to be silent about his desires and needs, to control other and keep his dignity safe, telling him that work and power and honor matter more than love and family. According to her, she sees no reason to treat him like a son instead of a tool since it's a “non-profitable task”, and that if he wants her to be a mother to him, he should be something else to her.
Their relationship was later shown to be much more abusive. Carolyn bordering on mentally and physically abusing Jumin to control him. Because according to her, Jumin was born the way she wanted him to be, perfect, with no twists or turn. However that made him “far from a human being”, making him nothing like a child, that “he’s exactly to way she wants him to be, but he's creeping her out”. Frustrated, she asked him why he can't have fun like other ordinary, unfocused, disoriented children. Jumin then responded with “You are the one who made me like this”. Which resulted in Carolyn forcefully locking Jumin up in a basement filled with toys on several occasions to get him to act “normal”. The longest time being 17 hours and 14 minutes. She was satisfied that he was growing like her, but at the same time she hated it, which eventually led her to avoid him completely.
“We both wanted an ordinary loving Mother-Son relationship, but neither of us had any love to provide each other with” - Jumin
Chairman Han
He is Carolyn's ex-husband, they were married for possibly 7–8 years. Not much is known about her relationship with him. However, it's known that she only married him for his money and high status, as she was described by many as a “gold digger”. They had Jumin together, and according to her, it was a planned pregnancy to produce the best CEO through the best genes, which also applies that she probably married chairman because of his smarts and good genes. Carolyn referred to their love as "tacky" and "cold", and their marriage didn't end well, having a very public divorce with Carolyn asking for an insane divorce settlement that caused people to label their divorce as “love’s betrayal”. And it was also mentioned that Chairman wasn't the most faithful husband, having married another woman immediately after their divorce, which only conducts that he has been messing around with other women while being married to Carolyn.