File sharing issue

Hello

With a young boy (with his own user) now using my computer, I want to make
sure that he does not delete any files. I have attempted to utilize file
sharing so that he can only read (but not modify/delete) files. However,
when I go into his user account, he is able to access the files through
explorer and delete them. Am I doing something wrong? The folders that I
have designated for sharing also now show up as a network resource. When you
view the files from his user through the network the file sharing permissions
work. What gives?

Thank you for any feedback.