Says who? The non-aggression principle is a limit on "expression"--you can't "express" something that violates someone else's rights.
I think the correct word to describe what you're actually thinking of is "libertine", not "libertarian".
Is hardly an example of what you're describing. She explicitly supported property rights and the non-aggression principle.
It's interesting, though, that she refused to identify herself as a libertarian because she saw those who did as anarchists. So she apparently had the same kind of misconception about libertarianism that you do.