Like Emily Thorne, Charlotte is intelligent, defying expectations in school with her perfect academic record.
The legal daughter of Conrad and Victoria Grayson, Charlotte is actually the result of her mother's affair with David Clarke.
Unlike the rest of her family, Charlotte has a moral compass and has never done anything to intentionally harm someone for her own benefit.
Subsequently, Charlotte has a troubled relationship with her cold, ruthless mother, and is torn between keeping her family together and trying to break away from them.
("Perception") Charlotte has a hard time dealing with the lies and betrayal in her family, and begins drinking and stealing narcotic pain-killers.
In "Reckoning", after a cold goodbye from her mother, Charlotte discovers that Victoria has been a victim in a plane crash.
When Conrad enters her room, he finds her unconscious on her bed with the pills strewn around the floor.
She stays there the whole winter and misses her mother's funeral, but convinces Conrad to let her go to Victoria's memorial service.
Charlotte arrives at the memorial, but after giving a loving speech about her mother, is told by her doctor that her blood has tested positive for a prescription drug.
Charlotte realizes that Victoria is as cruel as she remembers and leaves angry and hurt, which Nolan and Emily watch from a hidden camera from the car.
She instead spends her time with Amanda Clarke, who she believes is her sister, and the Porter family (including her supposed nephew Carl).
In the episode "Collision", on her 18th birthday, Charlotte legally changes her last name to Clarke in honor of her father.
A school friend of hers, Regina, speaks badly of Amanda, and Charlotte punches her at the Grayson Halloween Masquerade.
They sneak into clubs illegally, and Charlotte and Regina put on a show by kissing each other and allowing photographs to be taken which are revealed in the tabloids.
In "Truth, Part II", Declan dies, leaving Charlotte alone with their unborn child.
In "Fear" it is revealed that Charlotte has miscarried and has been spending her time at a Grayson home in France after learning of Declan's death.
Six months after Conrad's death, Charlotte and Daniel have been left penniless and adrift after the government seized all of their family's assets and Victoria apparently deserted them (in reality she was secretly committed to a psychiatric hospital by Emily).
Charlotte remains close to Daniel, but remains estranged from both Jack and Emily - she has started doing cocaine and is dating Gideon LeMarchal (Daniel Zovatto), until Charlotte learns that Gideon has been using her to get her money and was cheating on her behind her back.
Now totally despondent, she is apparently ready to jump off a hotel roof, but is saved by Ben Hunter.
Victoria returns to the Hamptons and is appalled to learn of Charlotte's suicide attempt from Daniel.
Unlike her brother, Charlotte accepts her mother back and shares her knowledge of Emily's identity as Amanda and confesses her own failed attempt to kill her, and she is now fearing retribution.
Victoria decides to bring Charlotte with her to come live with her and David Clarke - revealing her real father is very much alive, and the two will protect their daughter from Emily.
Charlotte is told David will find out about his other daughter Amanda's survival, but only when Victoria has set the narrative that "she viciously dedicated herself to our destruction and our suffering".
Charlotte continues to try and emotionally torment Emily much to Jack's dismay, but ends up being used as bait to lure David into a trap.
Charlotte promises to let Louise into Victoria's penthouse hotel room if the latter stops calling her.
Although Charlotte is originally sweet, friendly and charitable, the constant disapproval of her mother, learning that she is David Clarke's daughter, breaking up with Declan, the emotional abuse and lies of her family, and the presumed death of Victoria cause her personality to change to miserable and depressed.