See her video and download them
In WashingtonPost's article I see, "Once Rejecting Religion, Armstrong Now Sees It as a Guidepost" but at the middle of the article I see --- 'Sometimes I call myself a freelance,' she says in her melodious English accent. 'I can't see any one of the great religions as superior to others. . . . I'm seeking to make sense of life, looking for its meaning and how we can have a better humanity.'"
Obviously, from this I can conclude (to some extent) that Karen Armstrong is deliberately avoiding using the word God, she is infact neither disbelieving or believing God instead she chooses a pathway more apt to her nature called Compassion.
Karen can answer it better. Karen are you an atheist?
If you've any questions for Karen Armstrong let me know, I may get a chance to ask her Your (any/every) questions.