The Three Sisters Sister is a term used to refer to the three sisters from the play 'The Three Sisters' by Anton Chekhov. The three sisters are Irina (5 letters) and Olga (4 letters). Irina is the youngest of the three sisters and is portrayed as an idealistic romantic who dreams of a better life. Olga is the eldest sister and is portrayed as a practical, hardworking woman who is devoted to her family. Together, the three sisters represent the struggles of the Russian people in the late 19th century.