Mabel Cartwright is portrayed by Debra Mooney, in the fifteenth episode of the first season of Batwoman.
According to Mabel, she was beautiful when she was younger. However she "married the wrong man who never loved her and took too long to die". Mabel had a son with said man, August Cartwright, who grew up to become a doctor and with whom she had a mediocre relationship through all her life. When August had a son of his own who had facial deformities, Mabel treated him so badly that her grandson, Jonathan developed a certain level of fear for her.
Growing old, she became obsessed with her beauty slowly fading and developed a respiratory illness. In 2003, after her son fished out Beth Kane and the severed head of her mother, Gabi Kane from Gotham river, she started to ask him to transplant her the woman's face so she could regain her beauty, but August had no intention to give his mother the face of a dead woman so he kept it in a locked fridge just to satisfy her.
Living with her son
Sometime after 2004, after her health worsened to the point Mabel became bonded to an oxygen tank and couldn't live on her own anymore, Mabel was forced to move in with her son. After coming to his home she immediately scolded him for smoking his pipe while she had an oxygen tank and complimenting him for "fixing" Johnny's face, prior to demanding when he intended to fix hers, causing him to reply he was working on it.
She then began demand more and more things from her son, grandson, and especially his newly "adopted" daughter, Beth Kane aka "Alice" whose psyche had slowly broken due to her imprisonment by August, being forced to make skin masks, and being heartbroken over family's "abandonment." As Beth was a young girl who was blossoming into a beautiful woman, this attracted Mabel's hatred. Mabel began to treat the girl like a servant, savagely beating her when her tea was too sweet, pouring it on her hands when it was too hot, cutting out her hair, violently attacking her when she didn't get what she wanted to eat and making her address her as "your majesty".
In 2013, after years of tortures and abuse from her, one day, Mabel put on a pair of earrings and asked Beth for her opinion. Alice, recognizing the earrings as her mother Gabi's, asked where she got them which Mabel smugly said they were a gift from her son. After finding Gabi's severed head in a locked fridge in August's cabin, Beth came up to Mabel's room who demanded her to warm her tea. Instead, Beth broke Mabel's oxygen tank and used it as a makeshift flamethrower to burn Mabel alive as revenge for what she planned to do with her mother and putting her through so much abuse.
Mabel would be remembered as Beth's first kill which completely broke her sanity and led her to her to become the psychotic, murderous criminal "Alice", Alice is still haunted by the trauma she went through from Mabel's abuse. She appeared as a hallucination after Alice was subjected to a dose of fear toxin.
After Alice was betrayed by her sister Kate, and locked up in Arkham Asylum, she began plotting her revenge and vowing to take Mabel's place as the "Queen of Hearts"
At first glance, Mabel seemed like a normal, fragile, and tender old woman. However, in reality she had a mediocre relationship with her son and grandson and was truly a cold-hearted person, much like her son. Mabel was horrific and cruel to Beth Kane as she was jealous of her youth and beauty where she repeatedly abused her both physically and emotionally. And because of Mabel's cruel treatment of Beth, Mabel became the one thing Beth feared the most.
Mabel was also very vain and shallow as she cared more about her own beauty and was obsessed with the idea of losing it by getting old. Her vanity led her to be obsessed with Gabi Kane because of her youth and beauty. However, her obsession with her beauty would lead to her death after Mabel put on Gabi's earrings, leading Beth discover her mother's severed head before burning Mabel alive.