I agree that by nursing and co-sleeping you have to be ready for years of nighttime parenting, but I don't agree that it's doing your daughter a disservice. We have done this with both our kids, and a slow steady weaning from nighttime parenting worked just fine (at about the three year mark). Since you obviously can't leave the daycare kids alone, just pop your daughter in a sling or ergo or wrap carrier and go about your business. She will fall asleep peacefully and you can then lay her down. This will help break the nursing/sleeping association, but keep her secure and enjoying going to sleep. As the months go by, you'll be able to get her to sleep by laying near her and patting her back, you can practice this on your days off. Doing things differently day by day might actually help, as she will learn to sleep in different ways and different environments!