Transmigrating into a female supporting role in a book

The heroine travels through time and space to a rebirth story and becomes the female supporting role in the story. She is already married to the male supporting role who is obsessed with the original heroine. There is no cheating cheat, no system, only a little foreknowledge of the original plot. As an ordinary person who is greedy for modern technology, how should she deal with it after finding that there is no hope of returning home and wanting to escape from her current life? Slow-burning story, first-person perspective, CP, no blackening of the original hero and heroine. ...