In the homeschooling community we have families with more than the average number of children (the average is 4 and families with 5-12 are not uncommon) yet the majority live on one average income. Below average incomes are not unusual. They do it with no government aid and a large number of them have no debt at all. How? Living with different priorities.
They share bedrooms, eat basic meals, buy used clothes, give humble gifts, drive old vehicles, vacation in tents, own less expensive houses, etc. They live frugally and focus on their children over stuff and careers. They didn't live on two incomes before they had kids or down scaled mercilessly . That's why Mitch Stevens called the hs community "The Kingdom of Children" in his book.