If a couple has two children, each person in that couple has two children as well, not one. IE, if you ask a father of two how many children he has, the answer

If a couple has two children, each person in that couple has two children as well, not one. IE, if you ask a father of two how many children he has, the answer is "two", not "one; the other one is my wife's". So saying each person gets one child is basically equivalent to saying each couple gets one child, except there's no need to include the concept of a "couple" in the equation.