The Garden of Red Flowers

A story that reincarnates as a happy <supporting> in a friend's novel, but takes on the misery of <the main character>.
Venianne was living her life peacefully until she was reincarnated in her friend's novel as a supporting character. Luckily, she knew the story well and was happy to have stumbled upon a character with the future all mapped out. Why bother to go back to your old life when you can take it easy in a mansion? Except that her destiny did not seem all mapped out as she hoped... What if the storyline could be changed?