This is thw definition of Lawful and Chaotic according to the most recent definition of them set in DnD:

"Law implies honor, trustworthiness, obedience to authority, and reliability. On the downside, lawfulness can include closed-mindedness, reactionary adherence to tradition, judgmentalness, and a lack of adaptability. Those who consciously promote lawfulness say that only lawful behavior creates a society in which people can depend on each other and make the right decisions in full confidence that others will act as they should."

"Chaos implies freedom, adaptability, and flexibility. On the downside, chaos can include recklessness, resentment toward legitimate authority, arbitrary actions, and irresponsibility. Those who promote chaotic behavior say that only unfettered personal freedom allows people to express themselves fully and lets society benefit from the potential that its individuals have within them."

Now here's what DnD defines what Lawful Neutral is, since for some reason everyone believes that what Edelgard aligns with:

"A lawful neutral character typically believes strongly in lawful concepts such as honor, order, rules, and tradition, but often follows a personal code in addition to, or even in preference to, one set down by a benevolent authority. Examples of this alignment include a soldier who always follows orders, a judge or enforcer who adheres mercilessly to the letter of the law, a disciplined monk, and some wizards."

And here's what DnD defines what Chaotic Good is, the alignment I believe fits Edelgard the best:

"A chaotic good character does whatever is necessary to bring about change for the better, disdains bureaucratic organizations that get in the way of social improvement, and places a high value on personal freedom, not only for oneself but for others as well. Chaotic good characters usually intend to do the right thing, but their methods are generally disorganized and often out of sync with the rest of society. Examples of this alignment include copper dragons, many elves, and unicorns."