Sorry for the mix up. Trying to think why I had you down as an atheist.
A committed atheist would at the very least be someone who had a commitment to merely lacking faith in God. But I'm stretched to think about how that differs from being uncommitted. We may never find out since if atheists were to have a statement of faith it could well be "Ve ask ze qvestions, not you"
I'll bite, as an atheist.
I find the idea of being 'committed' to it somewhat nonsensical. The only rationale that makes sense as a path to atheism is that the various claims somehow don't make sense for one reason or another. To be committed to the idea that those claims don't make sense would be to somehow stop listening to the claims, to not just not care but to actively avoid hearing more in case something suddenly starts to add up for you.
I can guess that the 'committed' refers to the notion of following the evidence, having a rationale and the like, in which case it's not the atheism to which they're committed, but rather a rational philosophy - at best I think it's a clumsy expression, at worst it's just nonsensical so far as I can see. Ultimately, the only person who can tell you what she means is her.
Or the gods, obviously, because they know everything

O.