My daughter has been at nursery since she was 11 months old and she had 3 settling in sessions structured like this: Settling in 1 - one hour. I came in with her and she played while I chatted with her key worker all about her Settling in 2 - one hour. I came with her but then encouraged to leave as soon as baby settles. I left after about 15 minutes (I sneaked out and she didn't even notice I'd gone!😆) Settling in 3 - I fully dropped her off for an hour. These sessions worked well for us, but there was the option to request more sessions if needed. I'm surprised not all nurseries start with this graduated approach
With our settling session I said to my son I was going to the shop to get him something and then when I came back gave him that. Worked for us, he now stays all day and happily says bye to me in the morning.
Yes as suggested start to leave her and build up the time. I'd start soon so your daughter doesn't get too used to you being there with her.
Yes, I would have thought it would be a good idea to start by leaving her for 10 mins or so, then work up to 20 mins, then 30 mins, then 45, then an hour, until you can leave her for the whole session.