How to make relationships between users

I have the quiz module installed on my website. I have setup two user roles on my site, Student and Parents.

I want to make a view that shows the results of a parents children.

Now I have made two fields in the registration using the profile module.

The number of studentThe number of parent

These two fields are now available both for parents and their children. How can I fetch the results of a parents children using this relationship?

I'm thinking I should I say:Show the result of the users were the field "profile_no" is the same?

Is there a better way to make relation between two users?

Thanks everyone!