Update... 2nd baby is out and resting. Not as energetic as first baby, perhaps due to taking so very long to hatch? Sort of a swollen bump on its lower abdomen where the cord leads to and attaches to the eggshell. Is that unusual? I'm hoping that it recedes as baby rests. 3rd egg is pipped and resting. Peeps loudly.
I checked on 4th egg that I thought was gone. Far behind the first two, which pipped internally on the 11th. Movement was so slight, I wasn't sure I was really seeing any. I bit the bullet and broke in with a small hole, and baby was shrink wrapped, I think. Membrane was white and rather tough. I dampened what I could reach with a q-tip, and broke a hole through it, and within a couple moments, baby took a big breath! Can't quite see where its beak is, but it took a breath. I wasn't sure how to cover up the hole, but I put a piece of damp gauze over most of the opening, leaving a small air hole. Maybe 4th baby has a chance? I hope I did the right thing, going in. Seems very weak, and I don't see how it would have pipped internally through that membrane...