I understand what you're trying to say. The youngest siblings can have the advantage of seeings their older siblings success/failure and then attempt to emulate, or avoid that. They can also fall into the trap of being taken care of by the older siblings.

>> Especially when you have such a disparity in age: from 42 years old to 18 years old.

You're making the assumption that the successful children are all similar in age. They're not.

>> As a result, my oldest brother's only option was public school in an underfunded district for grades 1-12. College was out of the qusetion, even if he could make it!

None of your brothers classmates made it beyond high school?