^And you're basing this on what exactly?
Sorry, I have to go one part at a time, I wrote that kind of quick.
Valen didn't find Catherine right away is my assumption only, based on the
In Valens Name comic:
My name is Valen... and I have served my people like no other. I led them into fire... into darkness... into death... and they followed me without hesitation. They acclaim my victories and hail me as a great leader. They speak of my successes as if they are as infinite as the stars. And yet, for all that I've accomplished... I lie awake, listening to the screams of the dead and dying, those who are already gone, and those are yet to be born. A few words from me could avert the Earth-Minbari conflict. A warning to Delenn or Duhkat... But without the war, there would be no Babylon 4 and no Babylon 5. There would be no rallying point against the Darkness... and the Shadows would win, now and a thousand years from now. I cannot deviate from the circle of which I am a part. I am the beginning of the story, as Zathras said... and a prisoner of it. I dare not change the end. Still... it's been a good life... lives... over all. Delenn, Catherine, Susan, Michael... if any of you see this somehow.. don't cry for me. For in the final analysis, I've always been too hard on myself. I'll be content to let history judge me, and all that has been done in Valen's name. And as for me... I've received my own reward, because I've found her. At long last... I've found... her."
I think it's the "at long last" that makes me think she was found after many things and not right away. Also, as per
To Dream in the City of Sorrows, that's where Catherine got "lost". and it was in the time "anomaly" from the Great Machine, so she could have popped out the same age years later.
So based on that^ I continued with: he had a Minbari spouse, because I think Sinclair had some emotions for Delenn and being a new Minbari and instantly an important person, would have had fans and admirers that he may have found one or several (are Minbari monogamous?) that he had feelings for and children. Children that would be mostly Minbari but with some Human "contamination" and not "pure".
Then I extrapolated: then the scandal was that he located Catherine and left.
This guy totally redid the whole Minbari culture. Is from many sources.
He didn't do that with a Human wife, a race/species that Minbari never met and wouldn't for a very long time: My assumption again, based on Minbari pride and culture that were on display in any number of places, mostly the show.
He reorganized the castes, created the Grey Council, and started that Minbari don't kill Minbari thing. The worker caste was sub-Minbari before this, as well. This is in several places through the show, too and in
To Dream in the City of Sorrows.
Then Valen, a Minbari not born of Minbari, had to leave. But the gene pool was "polluted": And that followed from the above.
And specifically, I don't think Catherine ever was transformed, and any children if any children existed, were not mostly MInbari. The Minbari decendants would have been almost completely Minbari, say 85% or more, because the thing that creates the Chrysalis changes the person most of the way, but not completely. And this is all conjecture, I'm not sure how much is left of the original species.
It's wonderfully constructed and complicated. That's why B5 is the best show ever. And I say that with no sarcasm or hyperbole, I truly believe it's the best show ever made. Anybody can nitpick something here or there, but every show has problems. JMS himself said something like as long as the great and good episodes outnumber the poor ones, they are doing pretty good. So, it's not "perfect" nothing really is, but it's the BEST when taken as a whole. And I'm done blathering now.