I want to give this story a major revision... The plot won't change much, but I'll make it more reasonable.
Sen Shang transmigrates into a book and becomes a pitiful cannon-fodder supporting female character. She sets out to turn things around and win over her enemies, but accidentally loses her life again. What a sad story. (Not really.)
Then she gets another chance, and holy crap, she's still the same cannon-fodder supporting female character. Nothing has changed!
The heroine has a period when she suffers from a snake spirit illness. (Serious face)
P.S. Our poor girl who transmigrated into a book is called Sen Shang, and later becomes Ling Sen Shang. She has a younger sister named Ling Sen Xin. Together, their names make "Shang Xin"! ~(≧▽≦)/~
The original heroine is called Ling Sen Li. (Doesn't that sound just like a Mary Sue heroine? Hahahaha. Hiding my face and running away.)