Friends with benefits?

So I had a girlfriend last summer that I really liked, but she never really opened up to me or tried hard in the brief three month relationship. I was pretty lame, always trying to make her happy, pretty much desperate to get her to like me, to the point where I was depressed all the time because she always cancelled our plans and never reciprocated. Now, a year later, we have decided to become friends with benefits. I know many would argue that friends with benefits always ends in someone getting hurt, and the golden rule is dont have friends with benefits with an ex, but I feel no emotional attraction to her anymore. She feels none for me, nor has she in her whole life due to a childhood... accident. I honestly dont see her as being a potential girlfriend and while we will always be friends, we hardly ever talk anyways. She is very protected by her parents (despite the fact that she will be a junior in college) so I wouldnt be able to chill with her and develop a stronger friendship that would lead to affection. I cannot look at her and want anything more because I know how she would treat me. So yeah, based on this information above, how will this friends with benefits thing likely end? My friend says itl never work out, but I dont even feel worried at all, I cannot see how it would go wrong. So how will it go wrong?