Hi all. Longtime lurker here. I need to know that this situation will get better?

I've had a little girl (now 12 months old) in my dayhome for about two months now. She is part-time (3 days/week). Her parents rock her to sleep at home and get her up as soon as she wakes/cries. I made it clear to her parents (when they signed) that I don't rock kids to sleep and I've been sleep training her here since she started.

Two months later and she still cries for at least 15 minutes before falling asleep. I have a mandatory 2-hour nap/rest period and she never makes it to 2 hours. Some days, she wakes after only an hour and then cries/screams the remaining time. I have her separated from everyone else right now (each kid has their own room) but am hoping to eventually have her share a room with at least one other child. Is she always going to be a crier? Is there anything I can do to help her (without rocking, I can't do that with other kids that tend to come out of their room at nap time). Every Monday I feel as though I need to start from scratch again because she spent all weekend being rocked/picked up the second she cries. Parents are not willing to change habits at home.

TIA.