I'm sorry that this chapter proved to be so frustrating for you.  And don't worry about the questions; you're right, if you never ask, you'll never know the answers.   So, in response to your questions: Amanda Pringle is an original character, just like Miranda Wentworth is.  I used the name "Pringle" because it's known to be a family name in the magical community because of that old caretaker at Hogwarts, but I don't recall ever intending for her to be related to him. I'm afraid I can't tell you why she's afraid of being recognized because that's something of a plot point; if you choose to keep reading, you'll find out eventually. And I'm a little at a loss as to answer the question about her grandmother, though, because she's only mentioned once more after this.  I did always have a notion that her grandmother wasn't necessarily the nicest person, though, and that she had almost as comprehensive a knowledge of the Dark Arts as Snape had.

Oh santo cielo! I have suddenly understood that this is NOT a one-shot. How stupid of me. I thought that the story was complete, but I now I see that the real answers will come later. Thank you very much for such a long and detailed reply. Looking forward to the next chapters :)

Thanks. :) I do indeed; the story is complete in seven chapters, plus an epilogue.  I'm editing Chapter Two now and should probably have it posted in a couple of days. :)