Agreed. If it is any sort of layer feed, do not use it. Get a small bag of chick crumbles (unmedicated if they're with mom) for them. Partly, good chick crumbles are very small for tiny chicks to eat; partially it has a balance of nutrients that the chicks need to grow quickly and healthily. Mom will be OK on starter feed if you give calcium on the side.
If you give the baby chicks layer feed, calcium deposits will form in their bodies, making kidney stones and abnormal formations on the bones. They will not thrive and you may lose them quickly, or they may suffer along for months.