I haven't come across that information. I have read that if I handle them I need to put them back facing in the same direction as the sitting parent and be super careful a parent doesn't scratch them by accident. The kids are very excited. I just found a 9 day old one on YouTube being hand fed. Oh my goodness! Adorable! I've book marked it just in case.
They can hatch a few days apart but looks like these two will hatch very close together which is actually a good thing as they'll be the same size. I'll keep a close eye on the parents and make sure they are feeding them well as this is their first try at child rearing. But it looks like the babies are quite demanding, making a pitiful squeal as they flap their little wings.