Quote from Kajikami
But there absolutely can be people who choose to become religious without having been immersed in any of the dogma.
I personally know someone who grew up in an entirely atheist household, who became deeply religious in high school. She wasn't recruited by a religion or influenced by someone she knew; she decided there was something missing in her life, went looking for it, and found it in religion.
I've heard taller tales in my life, as they say, but the least I'd like to clarify about such anecdotes:
1. Being/becoming "spiritual," in a very nebulous sense might well occur in the absence of dogma. It is entirely possible some people are more readily able to enter meditative states, feel empathy, or something similar. I just wouldn't use the word "religious," here as that absolutely implies you've got the dogma hammered in and found that you agree with it or at least accept it despite obvious flaws. Nobody simply becomes christian without ever hearing of Jesus. Nobody spontaneously goes on Hajj without knowing of Mohammad. etc.
2. I would be QUITE curious to know what an "entirely atheist," background entails. Frankly, I don't think such a house exsits anywhere. For one thing, we've already clarified that Atheism isn't a system of belief, but rather a rejection of theism and it's belief system. I know very non-believing families who take their kids to church or synagogue just for the cultural and historical significance. Even in the absence of that, I think it would be impossible in the US especially to dodge some fairly serious attempts at indoctrination.
Ultimately, mid-life crisis and crisis in general can generate some of the most profound changes in our lives, but that isn't a positive affirmation of every change we make or the motivation itself. I would safely guess, in the case of your friend, she was being fed a lot of information about one religion or another from childhood or at least adolescence. When the crisis in her life came and she felt alone, the community of belief gave her something to be apart of.
I don't think human interaction or a sense of belonging is bad, so good on her. I just wish she (and others like her) would choose a group that didn't involve the surrender of the mind to irrational truth claims.