That she wanted them to hold onto Ignatius' heart — the egg — and decide, ultimately, when it should be returned, now that's the shocking part. Shocking enough that Childermass spends the discussion over it silent, observing the Ringmaster as well as the others here as they try and decide what to do with it. Yes, he could simply offer to hide it in his shadow, but that would not be a permanent answer.

But then the bigger egg is hatching and all that's left to do is to step back and hope Ignatius really isn't able to incinerate them all on arrival.