My son is currently a year old and I've used that book as well.
Before I go into my situation, just food for thought based on my experience (what little I have) and what that book says: I know that book says that some children still may need to eat twice a night until about nine months old. If you think she still needs to eat, you may want to try feeding your baby in a chair when she wakes and then putting her back to sleep in her crib after the routine and see if that reduces the number of wake up/feeding times.
As far as my situation - since he is my only child so far, I can't help you in relation to working with your other children's schedules, but I can tell you what finally worked for us. We started out in a one bedroom apartment because we didn't think we could afford anything else, and now that we're in a two bedroom and my son has his own room, I wonder why we didn't move sooner! Because he was in the same room as we were, he knew that he could cry and get a response. To top it off, my mother-in-law watched him during the afternoon so I could go to work and there was a lot of compromise between the two of us as far as feeding, napping, etc. She thought it was perfectly fine to continue to give him a pacifier for his naps (and any time, for that matter), even though I wanted to get rid of it after three months. I gave in on that one because she was being really helpful and watching him for free.
Around 9 months, we finally moved to a two bedroom apartment and I became a stay-at-home mom partly because my mother-in-law hurt her back and could no longer watch him. It was a huge relief when I finally had more control because my son was waking up anywhere between 3 and 5 times a night, mostly just to have his binky replaced, but also to feed once or twice and I was a WRECK. Luckily, he was always very good about going right back to sleep in his crib after the whole routine. When we moved to a two bedroom, it took about a week after we were settled in, but I succeeded in weaning him off the pacifier and he was sleeping through the night - between 12 and 13 hours!
For my son, the best thing for him was learning to fall asleep unassisted and to have his own space.
I can't really help with the nap situation. Because of that book, my son won't sleep ANYWHERE outside of his crib. Curse that book for that! I try to be consistent, but he still often cries a lot during nap time. Sometimes I'll go two weeks with perfect naps, and then for three weeks he'll refuse them. I don't really understand it. Luckily, it hasn't really affected his night sleep because I just make sure he goes to bed earlier when he doesn't nap well.
Good luck, and I hope this helps!