it's a nice thing to teach your kid programming langage!
I have several advises, ideas :
1: why use gif while those aren't animated, you could as well use png for those color styles.
2: second for your level layout, you can just store 1 value for wall and let decide the graphic render which part of your wall to draw (based on neighbooring cells), could even ...
I am looking for feedback on how to improve the professionalism of his code
how to be more 'pythonic'
The style you've used is atypical in Python as your code doesn't follow all of PEP 8.
For example you've used camelCase rather than snake_case for function names and variables.
Personally if your son wants to be a programmer, not a Python programmer, than ...