Back off and don't be so available to her. If she only wants friendship then you shouldn't be letting her cross friendship boundaries with you. Don't continue doing bonding rituals with her like cuddling in bed. That's just YOU enabling her to not have to change a thing... why should she when you're giving her all the attention already?
Be friendly but stop being her faithful Labrador retriever. She will never want to be more then friends with you while you're giving her all that emotional validation.
Don't forget that while you're all hung up on her, you'll never be open enough in heart and mind to pursue a chick that actually wants to be your GIRLFRIEND and not just your girl friend.
BTW: You said you both were in a relationship when you first came across one another. What's the status on THAT situation now?
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion