I don't disagree that there was some foreshadowing of the twist, but feels like the decision to include it came way later in development. Just replayed the whole game, and at the beginning her character is to explicitly taunt the mc about poisoning his dad and pinning the blame on him. It's only way later that she starts to hint about being pleased about the conquests, or randomly becoming pious. Meanwhile, the mc's entire motivation for conquest the whole game, while obviously being attracted to her, is to revenge himself on her for her actions. Only to then claim to want to marry her instead right before leaving before the invasion. This is before learning the truth about the queen, and after having no compunctions throwing every other leader and said sisters in a dungeon for less. Playing it all at once, both their motivations appeared to change abruptly way late in development to make her less evil and the mc less vengeful. Just my 2 cents.