determining that it was in the child's best interest for her supporting parent to stay in school to earn a degree that would result in a higher earning capacity

explaining that N.D. Admin. Code § 75–02–04.1–02 “demonstrates that a district court is not unequivocally bound to past earnings history if the evidence in the record demonstrates that such past earnings are not a reliable indicator of the obligor's actual present or future ability to earn income and pay child support” and “appears to be designed specifically for cases ... where the obligor's present ability to earn is not accurately reflected in ... earnings history”