Orgasms for females are very much tied into their emotional state. If your sole focus is on reaching this goal, she is going to feel too stressed out to orgasm.
Because she "isn't sure" she has ever had an orgasm, you can be sure she hasn't. She needs to be able to do this on her own before a man can do it for her. It is a matter of her getting to know her own body so she can direct your actions. Tell her she should learn to masturbate, and you should not be there. Your presence would only be a distraction.
Relax... I'll need some information first. Just the basic facts - can you show me where it hurts?