I Transmigrate into a Book as the Villainous Supporting Female Character in a Period Novel

[Transmigrate into a book + 1970s setting + take down scumbags + medical System + highly intelligent heroine] A gifted medical student from the 21st century earns her doctorate and has a bright future ahead of her. Then, after a night of drinking at a party, she wakes up in the 1970s. After 25 years of being single, she suddenly has a little girl and a man who claims to be her husband. Even more absurdly, she has transmigrated into a novel as a cannon-fodder supporting female character who makes life miserable for everyone around her. But after she arrives, her whole way of doing things changes. She cuts ties with her birth family and gets along with her in-laws. She had planned to be a single mother, but the man won't leave her alone. And the origins of both the child and herself are shrouded in mystery.