As I write this the month has flown by and we are nearly into May (tomorrow), I have obtained the web cam address so the pair can now be followed right up to fledging. She is still sitting tight on her nest tray on the 4 eggs, I expect that they will hatch very soon looking at the dates given earlier in the diary. I have been watching quite a lot over the holiday period and as yet I have not been able to see if any have hatched as yet.
The best bet is when she stands up to shift position, having witnessed this a few times I am still none the wiser, she seems to stay too low, hopefully over the next few days I can confirm if any have hatched.
Address of web cam is http://www.rspb.org.uk/datewithnature/146957-peregrines-at-the-tate-modern