I think what you are saying is that you regret asking her to be more than a casual date.
Now that you have asked her, you don't know how to turn the heat down on the relationship until you are sure you want to be more than friends.
I think the way to approach it would be to ask her out and if the subject comes up you can explain that you want to take it slow and date her and see if the two of you really click as a couple.
You didn't go into great detail about what "more than just a friend meant and until she gets back to you you are not "going steady" or "engaged" and your explanation will let her know you are interested in seeing where it can go.
