FYI in the future if you do need to brood them dont move them around much for their first week in my experience if you pick them up a lot or move them they have a high tendency to die. With mine we put a heat lamp in a plastic container then took a towel and made a mound with a little nest space on top, they hate being in the large containers and prefer to be crammed into small spaces (like the hollow of a tree). The mound allows them to climb up and down so they can get closer or farther away from the heat, but mine usually sat directly under the lamp.
They seem to die very easily from stress. Besides that not much you can do. I am sorry you lost them thats hard when they are your only ones.
Good luck with the birds next year, make sure to share pictures when they hatch.