I suggest that you wait until she is 15 if not later. Even though she may want to and you too, you have to wait until she grows up a little. I'm guessing that she is a virgin so it will be very painful but also an unforgettable moment. If you do decide to have sex (just by not writing it on your post I can tell that you are not ready) with her you HAVE TO HAVE TO use protection, for your safety but her hers even more. Do not even think about ejaculating when your ate inside her, since the sperm will go through the vagina. Tell her all this and even show her the post. The first time for a girl is VERY painful and there is a high chance of bleeding since her hymen has been broken. Her lower parts will also hurt and she may even experience it hurtful to urinate. This may be all the negative things, but please be 100% sure you want to do this. Hope you consider my advice.
Im 14, and i have had sex. Just give her time. If she wants to have sex, then dont force her. Just have fun with her i guess.