So exciting - I think there are six chicks. Mum has taken them a few metres from the nest to feed but called them back to her when she spotted me with the camera. This one decided to stay put though. Couldn't wait until tomorrow to post - sorry.
@hueymilunz That's what usually happens to me! However I've been out and talked to her each day and she's stayed put on the nest. She'd called all the others in and they were under her when I took this photo so couldn't really run away.