They have grown a bit in one week!
I moved them out of the blue rat cage base because they were kicking litter and poo and food everywhere. Now they are in a cardboard box with high walls. The light hangs a bit more safely now too, as it's not touching anything and we stopped using paper towel on the tray after the 3rd or 4th day.
They were constantly kicking litter into their water bowl, so I had to keep fishing out soggy paper pellets which was gross (and they look like poo when wet), so I elevated the water on a small box and that seems to have solved the problem.
Now they are consistently eating out of my hand and the kids hands. At first you had to put your hand in there and be quiet for 5 minutes before they'd come to eat food from your hand, but now they come straight to your hand to eat, which is really cute.
They are getting more feathers and some are even getting tail feathers!
The chickens are used to being handled, but if you don't hold their wings down there is a lot of flapping that makes you worry they are stressed. My son is scared to hold the chickens still but is happy to pat them and let them eat out of his hand, but my daughter loves to pick up the chicks and feed them and walks around the house holding them.
More progress photos next week!