I've seen her unthinkingly put herself in danger many times in pursuit of the truth.
There's a big difference, between putting oneself in danger to aggressively go after a story, and going to the ultimate extreme of attempting suicide. davejames
's point as to why the secret identity must be just a suspicion is spot on.
There's absolutely no verisimilitude in Lois's behavior here, unless part of her character is that she needs in-patient psychiatric treatment.