You have great thing going. Half of the men on AA would love to be in your position. But it is wise that you have asked your question. It shows that you are thinking with your head and not with your cock!
Six years is a long time to be friends. It does seem that your relationship has progressed from friendship to one with a greater meaning of being Lovers. You have not told us about the Love angle. Do you love each other or is it only from her side?
You have stepped into another zone when you both exchanged nude photos and have sex chats. You should be aware that a woman does not share her nude pictures with her face, unless she trusts a man. What does she have in mind? You must remember that few women pull down their panties only for the sake of sexual fun. They do so with the intention of getting a wedding ring on their hand. Are you prepared for that?
If you are lucky and she only wants to have sex, then you must ensure that she does not get pregnant at any stage. Read the questions and worries of the Members who had sex without protection and are now in a soup to understand their foolish actions.
Think long and hard about the consequences of baking your loaf in her hot oven.