Sonia Ramirez is Gloria Pritchett's younger sister.
In "Fulgencio", she and her mother visit Jay and Gloria shortly after Joe is born. She slaves around the Pritchett house, implying that her mother treats her like that back home. She implies to want to get out of Colombia after a flood occurred there and to escape her mother. Later, at Joe's christening, she and Gloria get into a fight over how Jay originally liked Sonia, not Gloria, but Gloria snatched the opportunity for a better life away from her.
In "Valentine's Day 4: Twisted Sister", she visits her sister and her family and tries to make a move on Jay, only to be heard via a baby monitor and the sisters resume fighting.
In "A Tale of Three Cities", she kidnaps Manny in exchange of Gloria's hot sauce business after finding out her sister took the recipe. It was later realized that the competition over their father's approval was the cause of tensions between the two sisters for years.
In "Perfect Pairs" She visits Gloria with her new artist fiancé Nestor after been running the sauce business for a while. Nestor is much younger than Sonia, and Gloria is convinced that he is after her money which turns out to be the opposite.