My nursery has an 8 week settling in period, about 3 sessions per week, for babies who start fulltime. My ds, exclusively bf and poor sleeper, was around also around the same age as your dd when he started.
It started with an hour with me in the room. Then extended to 2 hours, then 3 hours. Then I would leave the room but hover out of sight in the waiting room. I had to back track at this point, was called back and had to re-start.
After about 2 weeks, ds could be left reliably without being upset for too long. And they upped the hours apart to around 5-6 hours. By the time he started, the transition was seamless.
The only thing the nursery had to work on, which was not sorted by the time ds started, was naps. The girls cuddled him and held him for the whole nap time until about 2 months down the road when he finally allowed himself to be put down for naps without waking and crying.
The CM would probably have her own ideas about the settling in period so do check with her. 8 weeks was great for ds but I suspect a bit too long for most CMs (the settling in sessions were free for me, BTW). If you feel the settling in period is too short, you can always pay her the full rate before you start work and use Sept and Oct as settling in period.
I did not miss ds much or dd for that matter (year long maternity leave in both cases). It was a relief to finally go back to pt work - difficult babies.