Sonya is a middle-aged Irish woman with long, dark red hair and green eyes. She has small gaps between each of her teeth that define their shape. She typically wears a dress and, being a very conservative lady, she only wears clothes that cover most of her body.
She has a very gentle personality, instantly bonding with Dexter's young son who takes a fond interest in her. Together, the two act perfectly with one another and she knows just how to care for a child In Harrison's case, he's always an angel for her.
Underneath this exemplary personality, however, Sonya has somewhat of a suspicious nature. The worry that she is a creepy woman who might kill Harrison comes to Dexter's mind on one occasion when he comes home and finds that both she and his son are missing. As he plans on how to find her, she suddenly comes through the door with him. Dexter calms down but clearly Sonya is a woman who does not appreciate a lack of trust. She also did not appreciate Dexter staying out all night without informing her in advance. Because of this, she quits temporarily, but Dexter convinces her to give him another chance with Sonya describing it as a "leap of faith."
Sonya has a forgiving nature and her natural kinship to young Harrison allows her to return easily to Dexter's employ and is seen watching him like any normal babysitter.
In the events following Season Four, Dexter Morgan is faced with raising his son Harrison alone after his wife's murder at the hands of the Trinity Killer. With Cody and Astor staying with their grandparents, Dexter seeks out help to watch over his son so that he may continue uninterrupted at work and, more importantly for him, claiming more victims. Dexter and Debra have several interviews with less than desirable potential nannies before meeting with and hiring Sonya.
Sonya, in her time watching over Harrison, is shown to be a kind and considerate woman who takes a real liking to the boy. Although Dexter becomes paranoid when she takes Harrison out for a walk without notification (causing Dexter to believe that she kidnapped him), he comes to trust her with his son while he's away. She later assists in arranging Harrison's first birthday party, where she's seen taking part in the activities along with everyone else.
For unspecified reasons, she is not present in Season Six and is instead replaced by Angel Batista's younger sister, Jamie Batista, as the new babysitter. Sonya is not mentioned after this season nor is it indicated why she left Dexter's services.
- Sonya unfortunately fell into the category of characters that disappear between seasons. This is likely due to their contract only requiring their appearance for one season and/or Showtime deciding to drop them afterwards.
- "They decided to let Maria Doyle Kennedy leave the show because Scott Buck admits they "wasted her last year" (quoted from a forum interview of Scott Buck discussing Dexter season six).