I haven't been 'strict' (for want of a better word) enough to get my kids into a real routine, but when i have been, the feed-play-sleep has worked fairly well.

The only thing I can suggest to try is where does DD sleep? Is it in her own room? Just thought maybe if she slept in a noisier room (ie, the lounge or something) where you are that might help. Sorry, not much help I guess, but hope it improves soon for you.