MC wakes up on the sedan chair to be married, she realizes she is in a book she read before, and she's the side female lead character. Basically, two brothers are getting married at the same time and the FL arranges for the marriages to be swapped so MC has to marry the one that's scary. MC avoids disaster by staying with the scary brother instead of doing what the original in the book did. (Raised a fuss in the wedding room and basically becomes a concubine for the other brother since he had already consummated the FL)
Oh i thought it was because what you described is the plot for the 1st arc of the quick transmigration that i sent. Lol
I seem to remember having read a novel with such a plot, but I really don't remember the name First I would have said "I'll be the Male Lead's sister-in-law", but there the MC is transmigrated before the wedding... I'll think about it again
Are you talking about this one? in which in the novel that mc read before transmigration, side female character was killed by ogml to prove his love for ogfl. Later ogml gains memory of previous life (what happens in the novel).