Cintia Paiva
Eyes: Black
Hair: Blond
Race: Pig
Occupation: School kid
Legal status: U.S. citizen
Marital Status: Single
Known relatives: Dona Guida Paiva (mother)
Señor Paiva (father)
Base of operations: DuckburgStory: Cintia is the girl living next door to Biquinho, with her mom and dad.
Continuity: Disney
Company: Disney
First app.: Comics: Mickey #356 (1982)
Creator(s): Gérson L. B. Teixeira
Irineu Soares Rodrigues
Country of origin: Brazil 
Background notes: In the time period 1982 to 1999, when the stories with Biquinho were produced in Brazil, Biquinho was given the friend and playmate Cintia and her family as a supporting cast. In that time period, Cintia was often used in the stories, but after the production of stories with Biquinho was moved to Italy in 1999, the stories were changed and Cintia and her family was dropped and haven't been used since then.
There are no records of her being transferred to other media. Considering how much she was used in the time the Biquinho stories were produced in Brazil, it is highly likely that she has appeared as merchandise in some form.