She has money, given the heist and a shares, and again, child support. Not to mention, you really think high school kids aren't sexually active and all of them are going with safe sex? I remember back in high school there were atleast 3-4 couples who were having kids in their junior-senior year.
Also, I highly doubt we will be leaving the country any time soon, since your forgetting that the Carters would love for the MC to stay and attend college there, which is likely, among other things. YOU FORGET YOURSELF WITH THE LEAVING!