Creating relation between Parent and Student and Siblings

I am Facing problem in maintaining relationship between Parent and Student

For Example I Register a new Student 'A'who lives with Father 'X', I register a Parent Father 'X'..
after this on the profile of student it shows "Father:X" and on Parents Profile it says "Father of A" thats all fine.

BUT..
student 'A' has a sister 'B' which means 'B' is daughter of Parent Father 'X'

I am noticing that on Parents profile it says siblings and list 'A' and 'B' linking to their profiles both BUT Father Profile is not linked on Student Profile..

Moreover One more question...

On Registering a new student I selected Student Lives with 'FATHER' then it asked to register a parent.. it says
''Parenting Information for Student G (12)
Relationship _FATHER_ //as i selected it in students profile
# Resides with student
# Guardian"

But after this it asks again for Parenting Information
/*--------
Parenting Information for (0)
School No of Student * ____
Relationship *
____AUNT____
# Resides with student
# Guardian
------*/

What is the use of this infomation DO i have to fill "School No of Student" as 12 which here is the ID of the student and whose relationship is it asking..

I am asking all this as I think if Drupal has something good in it then it is Drupal for School