Tell your teacher that a past president of the American Name Society thinks "my mother created it by changing
Uriah to make it sound more feminine to her" is a perfectly legitimate meaning.
Of course in writing your whole report you can say what the original meaning of
Uriah in Hebrew was. That would be part of the entire history of your name. But it also is necessary to say that your mother deliberately altered
Uriah herself, because that is also an important part of the whole story of how your name came about.