(no subject)

If it were just Valeria, one could just say that Valeria was unable to have children. (Silk had no children in twenty years with Hyacinth, although he - or his body - produced at least two children in Gaon shortly after her death.) However, it isn't just Valeria. He had no children with the other woman he lived with over a long period of time, 'the tall woman', Apu-Punchau's wife/partner. (I take it she was that, since when he moved into the shaman's house, she moved with him.) At least I assume he didn't; with Valeria the lack of children is specifically mentioned; with the tall woman we have to assume that if there were any he would mention them, though as this is Severian you can never tell. You might just suppose Severian is unable to have children - but he refers near the end of UOTNS to 'my descendants'. The possibility that he had a child with Dorcas seems to be offered and then torn away from us. (When he sees her near the end of COTA she has a basket, and there are repeated references to babies in baskets. But when, a few chapters later, we find out how long he has been away, it becomes clear that if she has a child it can't possibly have been born yet.) I think there is a considerable amount of evidence that he may have had a child with Burgundofara - from whom he and a large part of the population of the Commonwealth are no doubt descended.

She does come from a dwindling family, but given the technology demonstrably available, the only real reason Sev + Valeria don't have children is that one or more of Sev, Valeria, or Inire exercised a veto.