She was the town's "book lady" or "just the bookstore everyone goes to" so it's obviously been a disappointment when that wasn't the case everywhere as I've moved on and visited other stores; but it's impressions like that, as a child and growing up with that you are left with an idea on how booksellers are supposed to be like because it's what you grew up with as the normal thing; but alas the world is large and I'm sure this author has his reasons.
Edit: wanted to add an example of how fantastic this woman was at figuring people out; I remember going in around maybe ~8-10 years old and she picked 'Edward's Eyes' [1] for me; it had a profound impact on me as a child as it was so similar to my own life, even sharing the same first name as the narrator of the book.