The Magic Shop: If Dudley Dursley had a Magical Daughter

Azalea Dursley is a normal girl. She lives in a normal house, in a normal neighborhood. She has strictly normal parents - even if they are divorced. She has normal grandparents, a normal aunt, and all-around, a normal life.

That is, Azalea had a normal life until her decidedly not-normal Great-Uncle Alvin dies and leaves her a music shop in his will. Why?

Maybe the answer will lead to something . . . magical.

Disclaimer: JK Rowling is a jerk. I do not endorse her views on Trans people. Also, Harry Potter and its characters/setting/plot don't belong to me. Only Azalea/other OCs.