[merlini]

it is fine if they do not eat for the first day, maybe even a second day. By day three they should at least drink or look interested in the food. Try millet, it is a cockatiel favorite. By ten weeks they should be plenty old to be adopted, I got mine even earlier (barely weaned).

They may be drinking or poking at the food when you are not around. Or at night. It is easier to see if they are eating any seeds by only putting a small amount of seeds in their dish, check it a few times during the day. Also maybe mark their water dish and see if it goes down at all.