It is not at all uncommon for a woman under 25 to have difficulty in having an orgasm .... there are many possible explanations for that, including that her body may still be maturing internally .... but my guess is that if she's not been able to bring herself to orgasm yet that she needs the time to get comfortable with her body and the sexual expression of her body. Maybe she's not comfortable with being "out of control" or maybe there is a moral code that is deeply etched into her being and it feels "wrong" to her currently ... the best advice I've heard so far is let her experiment on her own, get comfortable with herself without having to worry about you or your feelings or being watched, etc. so that she can figure out what works for her ... and that may not be a days, weeks or months kind of answer ... it will take her as long as it takes her ... I wish you well in the process.