Buffy the Buff Orpington hen has set once before, and she was wonderful. From 15 eggs she hatched 14 chicks (one egg had broken in the nest) and didn't lose one. But this time was awful! In the first place, the WL rooster was still young, so I don't think all the eggs were fertile. Second, about day 4 I accidentally locked her away from her eggs for over an hour in cool weather. Later, 3 eggs broke in the nest. All were already rotten. The first egg to hatch had something weird happen: the shell flaked off, leaving the membrane. Then it sat there for like over a day with no progress. The second did the same thing. I looked it up and found that the membrane can dry out and the chick can't hatch. I read carefully how to help a chick out, and thought I should because they were taking such a long time (and I had had an experience with a chick getting stuck in the egg before - long story). I helped the first three chicks out (very carefully and not all the way) and all of them died. All right, I decided, I should not have helped them. Hands off from now on. 3 more chicks hatched without a problem. But this morning I discovered that 2 of them were dead under her! She only has one left. I cracked open the remaining eggs. Most were rotten, but one had a fully formed dead chick inside! I realize now I should not have helped those 3 chicks out. What else did I do wrong? We've never had such bad hatching luck before, and we've had several hens set. Please be honest - I want to learn from my mistakes.