Coconut oil is an excellent moisturizer with anti-inflammatory and antibiotic properties as well.
Try to keep the chicks together. The sudden separation could send them both into further decline.
I would rig up a dirt bath inside for them both if it's too cold to take them outside. Dirt bathing is critical for feather conditioning.
Have you examined the skin and feather follicles for mites or lice? Use a magnifying glass and look at the base of the feathers and around the rump area. That may be a reason for the feather loss.
Crumbled tofu is a high protein, easily digestible food that most chickens adore. I would get some Poultry Nutri-drench which will boost their nutritional reserves immediately. Sprinkle it on the tofu. I would avoid the cat food since it's pretty heavy on salt and could further dehydrate them.
Try fermenting the chick crumbles for natural probiotics and additional nutrients. Just pour warm water over some crumbles, add a dash of apple cider vinegar unfiltered, and keep in a warm place, stirring a few times a day, feeding after 48 hours. Add more crumbles or more water to maintain an oatmeal consistency.
I would rig up a heating pad for the two chicks to snuggle against rather than put up a heat lamp, which might also be drying on their exposed skin.
With the kind of care and attention your daughter is giving them, I have no doubt these two are in good hands.