Sammi and Eddies back story

I wish we knew about Sammi and Eddie. I really can't picture Sammi ever liking him. Let alone doing it with him. They should have played into the fact that Eddie was older. She could have had a bad relationship with her Dad. Her Dad in the movie could be changed to her step Dad, who cares about her because she has looked for a father figure her whole life. They played into racism cliches, so why not the old father figure one.