I saw this on HBO in the 90s. It's about a girl in her late teens who is best friends with a boy that lives down the street. The title is a single word, and I think it's the girl's name, like "amber" or something. The boy and girl frequently break into British accents pretending to be other people. Eventually close to the end, the girl shows up on the guy's front porch telling him all the bad things the fictional girl's father has been doing to her. It turns out to have actually been happening to her.