The key to feed children from large/very large families is CHEAP and ECONOMICAL. There are food pantries and discount food stores which sell cheaper cuts of meat. Parents have to be ingenuous to find recipes that would find a large number of children. The staple in many large/very large family household is chicken(whether fried, baked, and/or roasted). Chicken is a very economical meat. Get the largest pound chicken possible(it's cheapest), have the butcher cut the meat-that should be enough meat to go around.
Also use hamburger and meat helpers to stretch macaroni and cheese and to stretch and add flavor to other vegetables. One can also use spam to add some spice and stretch vegetable, salad, pasta, and macaroni recipes. Make lots of salads, salads are very cheap and economical. However, the average large/very large families cannot afford a large variety of vegetables, but they can do wonders with cheaper varieties of vegetables. Or better yet they can use canned vegetables for many of their dinners.
Pasta is very cheap and there are myriad pasta recipes that are delicious and that children will never tire of. Use lots of water to stretch recipes to feed lots of children. Make use of casseroles. They are godsends to large/very large families.