Help needed: When do I intervene?

[Want Less]

We are on day 23 in our incubator with an egg that pipped yesterday early afternoon (so we are at about 18-20 hours). There was no progress on the pip for the first ~10 hours, then late last night the chick finally tore through the membrane and made a real hole. This morning the hole is bigger, but the chick is so far still not properly zipping. She's breathing and peeping and wiggling, but its more like she's concentrating on getting her beak out of the hole (you can see hole size in photo) than she is working on zipping.

I do believe that sometimes chicks for one reason or another are just not meant to hatch, but at the same time I'm willing to somewhat assist. I'm trying to keep the incubator humidity up to prevent drying since it is taking so long, but at what point do I consider intervening?

(Side note: we have one other egg in the incubator that just now on day 23 has pipped... I figured it was a dud until now. I'd think that something was wrong incubation wise (heat/humidity, etc) but we had 20 healthy chicks hatch on days 21-22.)

What would you guys do? If it makes any difference, this struggling egg was a shipped egg. The newly pipped egg is from our hen.

 

[ReikiStar]

If its been 12 hours since it pipped, we usually try to remove a little more shell and see if they can do it themselves. We had a chick who was too big for his shell. Even after removing 50% of the shell he couldn't get his head in a position to zip, but all others we've just made the hole larger and after a while they were able to king fu their way out.

(That big chick is now a strapping chunk...our Lavender Orp roo. No ill effects from helping him out except he did need to build strength in his neck the first few days, which they usually do while zipping.)

We'd be helping some more at this point. Sometimes you open it up a little and that's all they need. They start chirping like "thank you" and get back to work.