I recommend a novel called "As an Immortal, I Reincarnated as a Muggle". This fan-fiction novel tells the story of an old man who reincarnated as a Muggle and received an acceptance letter from Hogwarts, but the recipient was her sister, Harry Potter. In this novel, the female protagonist is a Muggle, and she and Harry are childhood sweethearts. The appearance and attitude of the female protagonist are also somewhat similar to what you mentioned. Of course, this novel also has a lot of fantasy elements. It's very interesting. You can come and take a look! I hope you like this fairy's recommendation. Muah ~😗