Oh gosh. I think you have to come at it from a different angle. Look at it from your daughter's point of view...just bear with me. I'm not passing judgment. Just think about why she's acting the way she's acting--they aren't very complicated creatures.
Every night she has this comfortable, warm place to fall asleep, feeling loved and protected. Suddenly she's set down on a hard, cold surface and left alone. Well, that sucks...time to wake up and ask to be warm and cuddly again. Except now no one is responding to her needs. She's freaked out and doesn't understand why she's alone and no one is answering her when she asks for help. For little ones it's a matter of survival.
It's not being strong willed! She wants comfort and safety and now the crib is a place where she feels unsafe and alone. So she wakes up every time because this isn't a good way to feel. Comfort and safety are valid needs, and she is letting you know that she has these needs. If you look up 'crying it out' and cortisone (stress hormone) levels, you will find lots of research that says that little ones left alone to cry have crazy high levels of stress hormones. It's traumatizing. It affects bonding. The stress may start to come out in other areas of her life, affecting her behavior.
Crying it out is hard for parents because we're not supposed to ignore our babies when they need something, even if it's something as tenuous as comfort. Children are learning to regulate their emotions and sometimes they need help. Ignoring them doesn't teach them to be self-sufficient. It teaches them that they are alone and that the crib sucks.
So, as a mom whose children (12, 7 and 3) have had no sleep issues, my best advice is to never let her cry it out. There are lots of sleep solutions out there that have nothing to do with leaving her alone to try to sort through her needs. The No Cry Sleep solution is a place to start. We slept with our babies. Our three year old still sleeps with us. It's sweet and wonderful and the kids love going to bed. We get lots of sleep and we have since she was an infant. Babies don't have to be so hard! Let it be easy. And transitioning out of the parents bed is no big deal if sleep isn't an issue. I promise!
It's fighting nature (hers and yours) to leave her alone--she's just letting you know what her needs are, and you're wanting to respond. I don't think she's trying to manipulate you--she just has a very strong need to be with you, which is the sign of a good strong bond.
Please do a little research into cortisone levels. If you want her to sleep in her crib it has to be a safe place for her. It will probably take some time to rebuild that trust with that space. And as for the post below, I don't think rocking your baby to sleep creates a monster. I think it creates a lasting bond that helps your little girl feel safe and loved. The idea that we have to train babies to sleep is nuts. We just have to help them feel safe, and sleep happens naturally. It feels good to be close. Your husband and you did a really good, natural thing. She's probably a happier girl because of it.
Good luck with it. I hope you find a solution that lets you all get a good night's rest, soon.