I like that people keep completely missing the entire premise of the story.
These are dragons. Dragons are all, in some way, screwed in the head. In the story, they are totally apathetic creatures outside of their relationship with their spouse and the aspect they govern, until someone disturbs something close to them, then they will strike back against said person for revenge many times over to an obsessive, irrational extent.
Its stated multiple times in the novel that Dragons don't give a hoot about human moral values and will act on their revenge with utmost impunity if someone offends them.
Its also mentioned that dragons would be utterly insane if not for defining themselves with an aspect
So what if person A did not do much to MC this life? MC wants revenge for all the suffering she has been thgough in all 5 lives. Just because they dont remember doesnt mean it didnt happen. The only thing that matters in MC and ML minds is the satisfaction of the revenge.
Got a child? Too bad all MC cares about is her husband. The entirety of the story its addressed that MC is being changed into a dragon's bride, and her morals and values change to that of a dragon. Its terribly irrational by human standards but the son and devils/demons/surbodinates understand because its part of the nature of the dragon to do so.