After Marrying the Frail Prince, the Legitimate Daughter Reigns Supreme in the Capital

[Transmigrate into a book + bride swap + reborn + palace and household intrigue + doctor princess + sweet romance] The moment Jiang Ruxu opened her eyes, she realized she had transmigrated into a book, and into the body of a tragic cannon-fodder supporting character! Even worse, as soon as she arrived, her reborn, vicious legitimate younger sister set her up, forcing her to switch brides and marry the Fourth Prince, another cannon-fodder who was living on borrowed time. In the original story, the Fourth Prince died from the start, and she was supposed to be buried alive with him! Jiang Ruxu: Fine, fine, you’re all the protagonists. I can’t afford to cross you. Surely I can at least run away? Wait, the frail Fourth Prince didn’t die, and her escape failed? No matter. If she couldn’t sneak away, she’d just get a divorce openly and honorably. Years later, desperate to keep his beloved by his side, the Fourth Prince secretly tried every deadly poison in the world, yet put on a frail, wronged expression in front of her. “They’re all trying to kill me. You’re the only one who can cure my poison. You wouldn’t want to see me die, would you?” Jiang Ruxu: Oh no, why does it feel like he’s trying to scam me into staying...