Earlier, I asserted Catherine (Severian's mother) to be the daughter of Valeria. So then, who's her father? It's Dux Caesidius, Valeria's second husband. According to Eata, Caesidius is taller than Severian (which would given Catherine her height), but looks very similar (hence the source of Cath's dark looks).
Ouen also tells us "Catherine" is an old-fashioned name and Valeria's family has been mired in the past for centuries. Valeria, also having no living relatives ("I am all the sisters we breed. And all the sons"), would almost certainly want to reproduce if she remarried.
Catherine also has access to the Corridors of Time.
As for who issued the warrant for her arrest (or more likely ordered her to remain confined), I believe it's Palaemon--but that's the subject of another post.
Re mantis' Cyriaca points: the reason I thought she might be married to Racho is because her husband is stated to be in Nessus (SWORD, p.44) and she is a former Pelerine postulant--which seems to link her to the race where we re-encounter Racho, which ends in the monial's tent cathedral. At any rate I can think of no other reason we should meet him twice.
Robert Borski