It sounds like you're saying she wasn't a libertarian because she labeled herself as an objectivist but a) it doesn't matter what she labeled herself as and b) it can be seen as just a subset, I struggle to think of any incompatibilities between the two, especially since libertarianism is used with much looser meaning.

The politics of Objectivism are basically Anarcho-Capitalism though, and you could think of Libertarians as more moderate, pragmatic Anarcho-Capitalists with achievable policy goals.

Basically, Objectivists largely support Libertarian policies, but argue that they don't go far enough.

This does not match my experience