Hi, I know it's distressing seeing how much condition they lose when hatching chicks. But she will come back. Don't be surprised if she moults after this.
Yes, she is taking the food and deliberately dropping it to teach the chicks what they can eat and how to forage. They need to learn all that from her. Poor battery hens never learn it.
I would not give them anything additional that is high in protein unless it's natural like earth worms or grasshoppers. Just the quantity they would find on their own if in the garden. I think cat food has too much protien for babies.
You can't really do much to make Mum eat more or anything else. She is prioritising the babies diets and lessons.
Chick starter is meant for new mums too. We give it to them before the eggs hatch so they get used to it and to keep them going. The laying mash has the calcium and protein she would need if she was producing eggs and she won't be doing that again for weeks when the hormones kick in.
I would just make sure that the mum and bubs have ample chick starter and supplement it with fresh scraps and fruit such as watermelon or anything mum particularly likes. Do you have them on grass? She might like the greens. My mums prefer a forage where they can scratch under mulch and leaf matter but still like a good to at the grass. You can start supplements/treats straight away. The chick starter from Northside Produce is designed for chicks of up to 8 weeks from memory. Laying mash should not be given to them until they are point of lay.
They will grow very quickly and will be more independent each day allowing mum to forage more for herself.
That's my two bobs worth anyway. I hope it helps.
Oops hit submit instead of edit.
I meant to say Too much calcium is bad for chicks. My point on protein is that the chick starter is balanced and if we give them too much then it is bad. As too much of anything causes problems and deficiencies in other things.
Also I think it is 12 weeks not eight that they should be kept chick starter for. I'd check with the produce.
Cheers