I don't know whether drilling down the message that "she is not gifted, she is just normal" is the right way to go. Maybe she will the get idea that she is not talented enough to try something so why bother. Alternatively you could reframe the message as "You are as gifted as anybody, hardwork is what matters".

A book won't change a person's life, but https://books.google.is/books/about/The_Adventures_of_Johnny... is a short manga (might not be suitable for the 4-year old but maybe the university student). Lesson 4 is "Persistence trumps talent.".

A summary of the lessons in the book : http://www.danpink.com/2013/05/the-6-essential-lessons-of-a-...