Hi, I gave birth almost 5 months ago to our 8th child; we are co-sleeping with him, just like we did with all of the others. I'm originally from Guam, and co-sleeping is part of my culture, and is pretty common in other cultures in that part of the world. I just breastfed until my body couldn't keep up w/ the demand; my baby didn't have any adjustment issues. Yes, all the kids just decided to sleep in their rooms (or in the living room, another cultural thing)when they were ready. Some were ready sooner than others, sometimes we wake up with the older kids in bed, like when they are sick.
I had a talk with the kids' pediatrician about co-sleeping--apparently the current APA guidelines state it is associated with a higher likelihood of SIDS, but when my next youngest daughter (now 5) was a baby, the APA was saying that co-sleeping reduced the chance of SIDS. Whatever. The way I look at it, each child and each family is different and the APA guidelines are just that--guidelines. You need to do what is right for your family right now, and try not to worry too much about being "odd" or not doing things right. Even with whatever you are doing now, you'd do things differently with every other kid you might have in the future, because each child will have a different temperament and will mature at slightly different rates. So you'd start feeding solid foods at different times, potty training at different times, etc.
Don't worry, kids are pretty resilient, and as long as you are loving your daughter to bits and paying attention to what she is trying to "tell" you developmental-wise, and as long as you don't try to force her to do something before she's ready (although it's okay to try to introduce her to new things!), she'll turn out just fine.
Honestly, I think out of all the mothers I know, the ones who are the most anxious (and with the most difficult children) are the ones who are so hung up on what this or that child expert says that they force their children to do things just to keep up with the guidelines. I hope I don't sound like I'm bragging because none of my children are perfect, but my kids (especially my older ones) all are comfortable talking to me about anything, even drugs, alcohol, and sex. Some of my friends have problems with their kids sneaking out, lying, getting drunk, etc. and I don't. My kids are pretty responsible, respectful, and considerate of others (at least when they aren't at home!) They love each other and protect each other when I'm not around, and they are comfortable enough with making their own decisions and deciding when they are ready to do things that they aren't slaves to peer pressure. They also speak up when they see someone being treated unfairly.
I think it's (in part) because we let our kids develop at their own rate while letting them remain "babies" for as long as they need to; co-sleeping is part of this equation. Do I really think that co-sleeping makes such a difference? Yes, I do. I don't think it's the co-sleeping per se but the underlying foundation of respecting you child's needs, nurturing them when they need it and respecting their personhood by allowing them to mature at their own rate. Anyway, sorry for being so long and rambling, and I hope this helps.