After transmigrating into a book and becoming the hero’s sister

When Jiang Chacha wakes up, she changes from a rent-a-job collecting rent to a high school student with no money in the 1980s.
From a socialist successor to the younger sister of the hero in the novel… Fortunately, she has a money-spending system, and she can still be a renter by doing tasks in exchange for money to buy a house!
As for the hero and heroine?
Love so and so!