You can't be responsible for her interpretation of things. She is going to hear what she wants to hear. If you were explicitly clear on everything: what you want and what you think and what you feel, there isn't really any excuses on her end. You've been thinking about this for a while so I think you probably covered all the bases eh?
And yeah, that's the tricky part of NC. It probably didn't go perfectly or how you wanted it or you think of something after the fact and then want to tell them that. There is always going to be some doubts but as I've learned the hard way, you have to just push on through it and not obsess over the minor details. She will only remember the big picture looking back on it anyway. I did obsess and it got me second guessing and going back and forth on my end and that just increases the confusion and the hurt.
Waking up next to a beautiful girl,
Step outside and say hello to my beautiful world.