Transmigrate into a Book: Helping the Second Female Lead Defy Fate

I'm a female actress.

I felt sorry for the frail second female lead in the screenwriter's story, so I transmigrated into the book!

I can only return if I successfully change her fate against all odds.

But the script has a bug: she suddenly has a pitiful older brother!!!

And it turns out he was born with the destiny of an emperor.

On the day he ascends the throne, he promises me the empress's throne.