Well, that was a stress about nothing!
It seems The Baby likes nursery! She did scream when she realised I was about to leave her, but she'd started to settle before I'd even left the room. The nice nursery lady whose name I've already forgotten took her off to read a story, and she was fine. The Baby's affections are fickle, and are easily bought with a crinkly book. And she was apparently fine all day. I think she really enjoyed it.
I really enjoyed it too. In fact, I feel slightly guilty about how much I enjoyed it. It's the first time I have left my one and only precious child with strangers, and I barely gave it a second thought once I'd driven away. The gorgeous sunshine and the fact that I got about 3 weeks worth of jobs done helped a bit mind. I almost gave them a ring at lunchtime, but only because I felt I should do a bit of an Anxious Mammy act, not because I was actually worried about her. I wonder if they thought I was really cold and uncaring for not sheeding a tear, or bothering them with frantic calls..
I am slightly concerned though. I think they have given me back the wrong baby. They have given me back a child who plays happily by herself, slept through the night, and has been smiling and laughing and giving me lovely cuddles all day. I don't know who she is, but I like her.