I would say that she is more of teenager although the book says she looked about 19 years old. So I let you decided on that. But Miranda is the 'maid' to the Dark sisters, she doesn't really have that much of lines, but she does come back in later in the story. She is a very monotone character for she is actually not even a human, but a clockwork creature. She simply fallows orders. If you get this part you will always be used for some random clockwork creature lines used in the story.

For her voice I would say to stay as monotoned as possible, and very little emotion in her voice. Although she is a clockwork creature, I would try to do it with a British accent, although if you can't do it then don't worry about it, I would actually like to her it with and with out. Voice range I would stick to medium for this character.