Looking for a manwha where a girl was born into a royal family with 2 brothers I think thats in a world that's really really sexist, since woman can't use magic I belive but later on the brothers protect and care about her aswell with the father.
I think it's this one. I could be wrong though cause I dropped it later on.
https://www.mangago.zone/read-manga/they_say_i_was_born_a_king_s_daughter/
I recall a little but of the plot but hopefully its enough for you all to help find its also i think quite popular aswell!
A Dukes daughter and was trying to stop a engagement from the crown prince becuase she realized all she needed was money and I also think one of the Love interests can Shift into a tiger and was bought off a slave auction.
Hopefully this is enough to be found!
The way she's all happy and nice to everyone the day she was gonna do it makes even more sadder because that's what most people do before they end it all.
breaks my heart