Responses
I get that the shitty dad is a duke and asking big retribution on him would have been hard but I agree with you.
She could have asked to at least become Lucian's main gardian so that the asshole wouldn't pull a move like that anymore: he has another heir anyway so it shouldn't be too much of a deal.

I wish FL made some countermeasures against the villains when she made that deal with the king. She could have wiped out her uncle and get her duchy back, and lessen Lucian's and Edwin's bio father's power so he wouldn't pull any more dirty moves.
Heck, I wish the ML was a bit more conniving so he could do some evil scheming and pull strings behind the scenes by planting his own spies to make the duke's as well as his loyal servants' lives difficult and drive them crazy so they would lose focus on Edwin and leave him alone. Then again, since he's a shiny golden knight commander, he's the honorable archetype so yeah, impossible for that to happen (except for kissing FL's hand in front of the duke's aide, which doesn't count in my opinion).