Need advice on what to do

Hi, I need advice on this matter, and I'll explain the details, a lot of which may be immaterial to this, so please stick with it. Okay, a little background; so I have met a girl on a site called VK (like Facebook) in April of this year and we got to talking and got to know each over really well. We then started Skyping almost everyday. I met her in Germany in August and then again in November. Now, I consider her to be my very best and dearest friend and I know that she considers me to be the same from her perspective. However, I am ever so very much in love with her, I, well, don't exactly know how to word that. So here is the issue; is it wise to ask her to consider being in a relationship with myself given the fact that we are best friends? Basically, if I ask such a question, could it be possible to remain exactly as we are now if she doesn't want to take this chance? Is it worth taking this risk and potentially losing whom I hold true to be the most incredible person I know, neigh, have ever met? Any help on this subject would be immesnly appriciated!

EXTRA DETAIL - Oh, and I live in England and she lives in Germany, so it would (should I actually do something and it works) be a long distance relationship. I don't know if that makes any difference to circumstances