I agree with what everyone has said here, you need to forget her and move on. And as for Faccebook, in my personal opinion, yes I would deleted her from your Facebook. Keeping her on there will make it harder for you to move on because you will keep going onto her profile and basically tormenting yourself. And please do not take offence to this, but I don't think she will be too bothered by it because it doesn't sound like the two of you interact on Facebook much. Good luck