I've had problems with this sort of thing in the past. I would meet a girl, everything would be all rosy and then I would become emotionally attached and stop doing the things that made her attracted to me in the first place. Eventually things would fall to pieces and I couldn't understand why but now I handle things totally differently...
There are two major things to consider here:
(1) Maintain your options - No matter how much you enjoy this woman you definitely still want to leave your options open. OPTIONS ARE POWER! When you know that if need be, you're fully capable of walking away at any moment, something magical happens...
You carry yourself in a totally different way. You maintain an attitude of abundance. You maintain a high level of standards (you don't put up with any bullshit). And because of this YOU MAINTAIN THE ATTRACTION.
(2) Stay on your path - Before you met this young lady, you had a bunch of things you enjoyed doing. You had goals and dreams. You had a path you were on. No matter how close you get to this girl or how great she is you need to stay on that path.
Many guys make the mistake of straying off their path just because they find some good tail. They lose contact with their friends. They don't pursue their hobbies. They stop being the guy who attracted her in the first place. Don't make this mistake.
Hope this helps.