Hey Annabelle - congrats on the first post, wont the last I hope - lol. It is a good site isn't it, although, there are some-times a few heated discussions or not so nice mummies with advice. Ah well, makes for some interesting reading at times.
I took the dummy away from DD when she started to wake constantly and search for it, but never have the skill to actually find it as such. I understand that its not always the best option though.
Other things I've come across was leaving a few dummies in with bubs, so they have a better chance of finding one during the night. Um, you could try and replace the dummy with another type of comforter - blankie, soft toy etc. Or, keep plodding along until bubs grows out of this stage and can easily locate their dummy and hopefully wake for you less.
Its quite normal to be nervous about putting her in her own room. I use to wake a bit more to start with, pop in and check on her. It seemed to take a few weeks before I would actually sleep properly. If there is no hurry, I don't see the harm in keeping bubs with you a bit longer (co-sleep, basinette etc). I think its important you are comforatable, other wise you will be stressed and not sleep properly. Is that a contradiciton - a parent sleeping properly???
Anyway, best of luck !!!
DD is 3yr 8 months - DS is 6 months