How do you do nap time? What activity comes before, and how is she put down?

Just from what you wrote, I'd go back to having her separate, and keep a very consistent routine (including what you do if she makes noise). The one problem napper I've encountered (I've been very lucky!) I moved to a floor bed (mattress on floor in a child proofed room) at 14mo and just kept walking him back to the bed if he got up, and if he cried I would give him a hug or pat til he calmed, then say I'd be back after nap time, and leave. I was very consistent, even if that's all I did for an hour, and now he's my best napper (goes right in and curls up, needs to be woken up for snack). To this day (23 months old) he has never napped for anyone else unless they slept with him or wore him. His parents wanted me to wear him, and I'm so glad I tried harder. Someone here gave the advice "begin as you intend to finish" and that plays through my head all the time!