Just for future reference, an internal pip looks like a triangle shadow in the air cell. There are some great pics here on BYC somewhere, when I find them I'll post the link for you.Number 4 hasn’t shown any movement or pipping today. I am going to do a quick candle to see if it has pipped internally.
Well, I candled the egg in less than 30 seconds and returned it. I don't know that I learned a lot; I can't tell if it was pipped. Just looks like a dark shadow and the air cell, it kind of looked like something was going on, but I don't know if I should make a safety hole before I leave just in case. I will just leave her in there for another day and see what happens. Maybe she is shy and will hatch in the night, or maybe she wasn't meant to be. Hopefully I didn't do any harm by candling her really quickly. The incubator was hot and humid when I returned her, and she was only out for maybe 30 seconds tops. I can't imagine it is any harsher than being kicked around incessantly by her siblings!