Such over-engineering does not smack of interesting material for a site called "hacker news". This is great material in itself, especially considering the context of education here.
Oh, advancement through self-education? There's practically zero pedagogic content on HN. Or in this submission! How did the father guide his daughter? Through examples & showing a restricted subset of the problem? By following the technique in How to Solve It & steadfast avoiding showing the student anything but patiently & gently reminding them of what they know & which skill to apply in each circumstance?
Oh, advancement through self-education? There's practically zero pedagogic content on HN. Or in this submission! How did the father guide his daughter? Through examples & showing a restricted subset of the problem? By following the technique in How to Solve It & steadfast avoiding showing the student anything but patiently & gently reminding them of what they know & which skill to apply in each circumstance?