I hope I’m not blending info from several books, but here goes:
I read the Braille version of this book—probably about 200 pages in print—in the early 1970’s. I don’t remember the title, and am on the hunt for books I read as a young person—to re-visit them through older eyes. The protagonist may have been named Kathy Hughes or had a friend by that name. She solves a mystery using library newsreels. There may have been a male co-sleuth. Finally, the book may have featured an elderly character in a wheelchair, Mrs. Smallett. Alas, that is all I can remember!