In some ways, I'm not sure how your story relates all that well to your story about your friend. I suppose in some fashion we are all guilty of this convenience, or shrugging off of what might be troublesome. For your friend in this case it could pose big troubles--she has recently converted over her beliefs to a man I presume she has pledged her life to, so at that level we're talking about much more than anything thought-provoking.
Does that make any sense? She has invested herself into what she hopes will provide her happiness, so it's much more than convenience. Well, to your view of it, it's a convenience for her to avoid the issues; to her it is a necessary support in what is her life.
Forgive me if I'm not being clear here. I'm agnostic myself, but strive to imagine myself in the other person's position. I certainly never accomplish that completely, but when I try to imagine it here, I can see how her behavior is still human, complicated, and perhaps not convenient as you seem to define it. Also, it seems likely that since this is a change from what you knew her to be like, you are likely to notice sharply those things which don't jibe with her past views and behaviors.
So I doubt that she has actually stopped thinking about things. Have you ever really stopped thinking about things? Or perhaps your thoughts move to new thoughts and you think about those?