Can someone explain what happened? I'm confused af I don't even know where to start. So fa...

Father married her mother (not sure before or after) her family killed his true love that he had a son with. Her mother loved him to the point that she adopted his son and raised him but he wanted to kill the mothers family leaving only the princess so that others couldn't fight for the thrown with no true bloodline available.
She is trying to get revenge on her father for killing her whole family and take back what is hers. Father is trying to take everything that is hers and give it the love child to spite the death wife. Father married into royalty, mother is/ was royalty.

Okay so from what i understand it goes like this:
The Empires Imperial/Royal Family are decents of the Sun God. The Grandfather (Man with red eyes that died) Was the previous Emperor. His daughter is our FL mother (Blonde woman who died).
FL mother (Emperors daughter) married (Blue/Black hair and golden eyes) Man. He was a knight I think. And the Mother was in love with him.
The Man ended up having a child (His son) with another woman and made the FL Mother pretend it was her son. The only child of the man and the mother is our FL.
The man hates the Imperial Family and killed both the FL Mother and Grandfather. Then the man made himself the temporary emperor until his son becomes the real emperor.
A lot of aristocrats didnt like this because only those with imperial blood should be on the throne. All those that rejected it died.
Everyone thinks that our FL brother is royalty but he is not (since father had a child with another woman).
Our FL is trying to take back the throne from her father and half brother.

I'm pretty sure it was after, considering that Paris is older than Nia, given that the story stated she was second in line to the throne:

- The story that was made up about Elenia and Gaius having a son was meant to establish him as having a right to the throne. But if the son was actually younger and the second in line himself that wouldn't help his case much (since it's apparent that this empire follows the direct line of inheritance - more on this following the asterisk after this (*) one. Also the made up story wouldn't make much sense if Paris' was the older one yet not the son mentioned in the story. The story was also clearly talking about before their marriage. Otherwise the citizens would have questioned the details about the late emperor not acknowledging a marriage between them and only acknowledging it after Elenia 'gave birth to her son' and returned home (sidenote; and, even if Elenia had, using some sort of logic, actually given birth to the FL while married to Gaius before the events of the made up story were supposed to have taken place, then that means the late emperor didn't acknowledge his granddaughter while acknowledging his grandson, yet it should have been clear even to the citizens exactly what kind of relationship the grandfather and the FL had)).

- Nia's mother gave up her right to the throne presumably for Nia's uncle (to most likely serve as temporary emperor until Nia came of age. *Because the grandfather viewed Nia as his heir). Despite the father being misogynistic af it's clear that the empire itself is not. Especially since women have a right to the throne in the first place. So that would mean being second in line simply makes Nia younger.

Well if FL Mother was going to pretend that the son was hers, the child would have to be born while they are married. I think our FL half brother is older than her. And wow i didn't know that the family killed the Mans love i guess thats why he hates them so much.

How does it mean that? Like I was saying she simply treated the son as her own in order to help her own younger brother inherit the throne as well as to get Gaius to look at her. Also like I was saying, the story they made up about Elenia and Gaius meeting and running away before Paris was born, then returning after he was born, wouldn't make sense if they had already been married. And if the story wasn't believable a lot of citizens would begin to question it, which wouldn't be good for Gaius. But that hasn't happened.