Jahlee and Merryn
Just reading the part in RttW in which Jahlee and Merryn and Silkhorn and Severian are together in the Matachin Tower. Some have taken Merryn's statement regarding Severian, "He's my brother" at face value as a solution to the BotNS mystery of who is Severian's twin sister, Severa. A simple, neat answer.
I tend to agree with Borski who, in Solar Labyrinth, argues that perhaps it is too simple and neat. Actually I think Borski misses some clues in this scene that additionally support his candidate for Severa- Jolenta.
Jahlee's mention of Merryn's difficulty with animals and Severian's perception of their shared witchiness seems to suggest a connection between these two characters and generally, I think, between witches and vampires. This connection is supported if we trace the European witch and vampire legends back to their Greek roots of the goddess Hecate and her lamia companions.
Just before the cell scene, Jahlee is teasing Silkhorn asking if she'd be better as
a brunette. I think this calls attention the fact that she is currently a redhead (if I remember correctly). Next she asks if she should give herself bigger breasts and a smaller waist.
Jolenta (perhaps a stage name) is a red head with large breasts and a small waist. She plays a character named Jahi on stage, who is a vampiric demon, perhaps with fangs. Maybe Wolfe is trying to use a Jahlee/Jahi vampiric association to connect Jolenta with witches here to provide clues that she is, indeed, a primary consideration as Severa.
Severian sees an adult Merryn when he is a child and the possible suggestion that she's
had something akin to facelift surgery is evidence that she is too old to be Severian's twin (assuming no cloning is involved). The RttW scene also notes that Merryn moves like someone "stiff with age", further disqualifying her and elevating Jolenta as a Severa candidate.
[some wild speculation, just for fun- I've been told by people of the time period that
The Exorcist, book and movie, had a huge impact on American Catholics. That story involves a battle between Father Merrin and the wind demon, Pazuzu. In Babylonian mythology, Pazuzu was in conflict with a witch/vampiric demon named Lamashtu. Possible Wolfe inspiration?]