That's a lovely dress, and your grandmother sounds like a lovely (and energetic!) woman! My grandmother sewed a lot as well, and when I was little she would always take me upstairs whenever I visited and have me try on some of the dresses she'd made for her daughters and then send me home with a bunch of them, so I always got on the plane dressed I was in a movie about the 1950s. I wish I still had them. She never made anything Jane Austen-ish that I know of but that dress looks perfect for a scene from a JA movie; probably a casual day dress that can get muddy at the hem from lots of walking :). ("Her hair, Louisa!")