1. Create a record query
  • On the Criteria tab, select:

    Record, Record type equals Individual

    AND Relationships, Relation, Relation record type equals Student

    AND Relationships, Relation, Student, Relation current grade does not equal Graduated

    AND Relationships, Reciprocal one of Father, Mother, Stepfather, Stepmother, Guardian

Note: The Reciprocal is user-defined. Those listed above are examples; yours may vary. Select values that would indicate the responsible party for a student without a parent.

The criteria above only works if you change current grade values to graduated after the student graduates.