K.
It doesn't sound like you're doing bad with the bedtime routine... I can share ours with you and maybe there are some elements of it that you'll want to adopt. Or not. Anyway, here's what we do with our 21 month old son:
Finish dinner around 6:30
Bath (with bubbles or whatever else he wants) - we don't worry so much about getting him clean these days - he likes playing in the water.
Tooth brushing
PJs and we read books. He gets to pick out as many as he wants. We usually read either sitting in his bed (he moved to a big boy bed at 19 months) or in the rocking chair.
Once we're done looking at books we turn out the light and sit in the chair with his blanket and lovey. I sing him some songs and always finish with the special song I made up for him when he was born (and that ONLY gets sung before bedtime). Then I lay him down, kiss him goodnight, and leave.
When we first moved him to his big boy bed it took a week or two to get him used to falling asleep alone in the bed. For a couple nights I laid with him. Then I sat in the rocking chair until he fell asleep. Then I lurked in the doorway. Then I put a gate up at the door and we battled it out for one long night where I refused to lurk. The next night I only had to put him back in bed once before he fell asleep, and by the third night he stayed in his bed himself. You may have to do this with the co-sleeping if you're not interested in laying with your daughter until she falls asleep.
When we were ready to drop the evening nursing I just moved it to before the bath instead of after the bath, and eventually he had better things to do.
Key things I think are:
1. set bedtime (around 7:15 for us) - kids get tired even when they don't always act tired.
2. Low-key activites onlyafter the bath. No more playing with toys as this gets him wound up again.
3. Consistent routine. He knows when we turn out the lights and sit in the rocking chair that it will be time to sleep soon. He knows when we sing him the "James" song that that is the last thing before we kiss him good night etc. Falling asleep is a conditioned reflex (as long as you're tired) - people rely on environmental cues - bed, darkness etc - to help them make it work.
Good luck!