Rose decides to move into the biggest lot in Riverview, because she heard it had plenty of places to fish. However, she was a bit ambitious, and only has 1800 simoleons left. Drag. It means she doesn't have very much to build a house with. Her "place" ends up being a toilet in a room and a bed that has an energy level of 7, so she can spend more time fishing.
Right after building the so-called house, Rose moves right along to get a job at the Soil and Water Research Facility so that she can fulfill her lifelong dream to become a Creature-Robot Breeder.
And then, as you probably guessed, she finds her way to the Riverview Fish Hatchery, where she can fish all day long and never get bored.
This goes on for a few days. Going to work, visiting the Hatchery, and then going home to sleep in her bed with various stops to the Firehouse or Gym in between to get a shower and a meal. Then, Rose decides to go across the street to the mansion and meet the man who lives there.
His name is Jon Lessen, and the two of them immediately hit it off. She finds him very attractive, even though he's quite a bit older than her.
By the next night, Rose asks Jon to move in with her, and they add onto the little bathroom home she had for herself.