I'm not a CIO mom at all and neither is my husband so we agreed on that from the very beginning. Nursing your baby to sleep is not a "bad habit" to break. I nursed my older daughter every single night til she turned 3 and at 3 she potty trained so I night weaned her and she just rolled over and went to bed. And now at almost 4 she is a very intelligent, independent and wonderful kid and sleeper. My son will be 2 on Sunday and just recently he stopped falling asleep at the breast, not so much because I stopped him but because he stopped actually falling asleep and just wanted to stay up and nurse all night! So I decided to stop him and he would fool around a little bit and then just go to sleep eventually.
Self-soothing is a term that the CIO camp invented to justify letting their babies cry. It doesn't matter what you call it, crying is not soothing any way you look at it. It wasn't right for me or my children and I'm confident that no baby "needs" to cry, just that some parents are choosing to use this method. You should't feel that your baby is somehow inadequate because she doesn't happily play in her crib alone and just drift off to sleep. Those are the babies in commercials :)
I'm not saying that there aren't some babies that are that easy going and will just go to sleep on their own but they are the exception to the rule.
You don't seem like you want to let her cry, you just think that you should do it because you've read the book on it. There are plenty of books that don't use this method and most of the world doens't for that matter. Plenty of developed, and un-developed, countries bed share with their children and nurse them to sleep and their kids turn out to be productive and happy citizens. Our country has so many older kids with tons of sleep issues and I don't think it's coincidence to say it's because they are more insecure because they never slept close to their parents and were forced to cry all night long.
That being said, I don't think a little cry it out can be harmful, for certain babies. I know my older one never would have responded to it and had I forced it, she would have certainly become detached. Had we believed in it, my second child most likely would have learned to STTN at a much younger age but we chose to respond to their needs day or night.
I'll step down from my soapbox now but if you'd like to message me to talk about non-sleeping babies, I could write the book on it :)
Best wishes for peaceful nights,
M.