Cry It Out?

My daughter is four months old and HATES naps. She used to never take a nap and I would spend almost an hour trying to get her to sleep, and all she would do was cry. I never wanted to do CIO, I thought it was terrible to let a baby cry, until now. A few days ago I put her in her crib for a nap, and she cried for about two minutes tops and then just fell asleep. I didn't have to pick her up, or give her a paci or anything, I just kept an eye on her from my bed. Is this okay? I'm getting different answers online, some people think 4 months is too young, others say it's fine. What do you think? Everytime she's only cried for two minutes or less.