She does not believe in God either.
You are right, she is an atheist.
What I didn’t know until I did a search to verify your statement, was that atheists have purity tests, many are suspicious of her full commitment to not having faith. LOL, it all sounds very strange, here is one of them discussing her.
http://www.thegoodatheist.net/2010/05/18/is-s-e-cupp-an-atheist/