First time hatch

This is my first post but I have found these forums to be a wealth of information in the past. To cut a very long story short, I am on day 22 with what started as 9 eggs under my remaining hen. On day 19 there was a dead hatched chick out of the nest. It was still wet. On day 21 whilst I was hand feeding the hen I was surprised to see a very happy & healthy chick pop it's head out. I gently lifted the front of the hen a little bit & saw unhatched eggs. When I changed the water last night there was another dead chick thrown out of the nest half hatched. The Chick was covered in yolk and it's head was still in the shell. I can't hear any chirping & mum is not moving off the nest. I don't want to interfere too much but don't know if the other chicks will be okay if I just leave mum to do her thing and am anxious that everything is going ok. My other hens were killed about a month ago and now I'm anxious that I'm doing things right.

 

thank you all for your helpful replies. I only have the one hen. I live in a suburban house and a few weeks ago had a predator come through. Have since found out I wasn't the only house affected. I'm not sure if the photo works but Bella now only has half comb after the attack. Which is fully healed and the reason she got the eggs was to stop her moving around & re-injuring it. Have two chicks!!! Will limit my interaction to changing water and feed and hope for the best. Will raise the edge of the box. I love my animals and am glad I joined backyardchickens