Emergency! Should I assist or leave alone?

[KellyDel]

I had 10 eggs under a broody hen. She crushed 3 fertilized and 2 non fertilized along the way, so 5 remained. I let her go to day 25 and no signs of pipping so I decided to throw in the towel. We removed all the eggs and my daughter wanted to investigate them, only to crack one and find that it's alive! Tried giving it back to the hen but she started pecking at it so I rushed it into the incubator. There is a crack w a bit of blood (not too much) and a large portion of shell is gone, white membrane exposed. It's been in the incubator and moving for about 12 hours now. I have the humidity up high at around 78%. My question is should I let it be or try to assist hatching? It hadn't externally pipped yet so I don't know if she's ready to hatch, however I'm afraid of shrink wrap with being so exposed . I appreciate any advice!

 

[NatJ]

Have you read this article yet?
https://www.backyardchickens.com/articles/guide-to-assisted-hatching-for-all-poultry.72886/

It has a lot of good information, and might be useful while you're waiting for someone with more specific knowledge to respond. (I don't know much about assisting an egg to hatch, but that article is widely recommended on this forum by the people who do know!)