So how many chicks do Rosie and Suzie have between them? This looks to me like 13! There is no sign in this picture of an unhatched egg but if there are any then they will have been shoved to the bottom of the nest cup.
This shows that there is at least 1 unhatched egg!
Another shot of 13 chicks.
Definitely 13 here!
This is a rather better picture taken half a second later, but the chick that is being fed is hidden by the parent feeding it and so is not visible in the picture which shows only 12 chicks.
Thirteen again here. Twelve gapes and one closed beak just visible below the gape in the top left of the picture.
Again, 13 chicks. Ten gapes and three closed beaks.
Turning to Box1, here there are are seven chicks visible.
Although one of the parents is trying to settle down on the chicks for the night, two of them are still demanding food.
I doubt that it is serious though!