Fiona is a friend of Jonas in the same age group who spends a lot of her community help time (a requirement) in the House of the Old. She is attentive and caring and able to relate to the aged in a way beyond her years. At the Ceremony of Twelves (a coming of age ritual, though void of religious connotations), this gift in her is acknowledged in that for her Assignment (job for life), she receives this task officially from the Elders.
Once Jonas had a dream concerning Fiona in which he wanted to bathe her in the washing chamber of the House of the Old, but she would not let him. At this awakening of his libido, his parents instruct him to take pills (which all adults take) to suppress his sex drive. Later in the story when he decides not to take them, this is his first individual choice against the instructions of the Community.