Answer:
Well first of all remember: Ex 20:12 Honour thy father and thy mother.
Second, the Bible tells us in 2 Corinthians 6:14 Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?
That does not mean to stay away from unbelievers (we should be around them at least to tell them about Jesus) but it does mean do not date or start a relationship with someone who does not have the same relationship with Christ as you do. Does this 14 year old girl know the Lord in a personal way as you do?
If she is a Believer then I am certain you can find things to do with her that are in a setting that would include other Believers and/or your parents or youth leader. I have a 14 year old daughter and she knows several great 16 year old young men who are Believers…still I would not be comfortable for her to go out on a date with them but would welcome them over to do something with the whole family, just not alone. You sound like a Godly young man and I am sure you can understand how it is so important how others would perceive your relationship with her. Be a good Christian friend to her and if she is someone God has picked out for you she will be SAVED and available at a time that is right for both of you and to honor your parents wishes.
God Bless,
Pastor Brad