I've been re-reading the entire series and noticed that in this trilogy (I think in The Bishop's Heir?), during a discussion about why the Castle Coroth staff don't trust Richenda enough for Morgan to appoint her as chatelaine, it's mentioned that in the case of his death, then Richenda would get to be the regent of both Marley (for Brendan) and Corwyn (for "Duchess Briony"). But in the previous two generations, the Duchy was in abeyance because Alyce and Stevana couldn't hold it in their own right-- did Donal or Brion change the law to allow women to inherit the title?
Or for that matter, ISTR a discussion from the first trilogy that before Morgan was married, his death would've left the McLains as his next heirs, which would a.) skip Bronwyn and b.) suggest that Kelson changed the law after High Deryni-- or is that just the result of backwards-disremembering the discussion in TBH about Morgan as Duncan's possible heir to Cassan, but with a junior claim to the Quinnells?