i could tell two versions of the origin (ooo sounds like a part of a Star Wars prequel film).
Version one: I like the song 'Paperback Writer' by the Beatles. I like the name Martha (that was my character in a play once-she was a flirt and could yell very loudly, fun times). My favey number is 23 (because I once told my friend she couldn't take over the world till she reached 23-'you can also climb ladders!' ahahahaha...well it was funny at the time. ahem.) Sorted.
Version two: a dedication to Martha, a little girl who was forever trapped in the pages of a book. It was a paperback: thin, red cover with dog-eared page corners. She had been read many times. It was a simple story: Martha goes for a walk, past the river and to an old cottage in the woods. There her friend Harry lives. They have a pleasing meal of scones with jam. Simple words for small children. One day the Paperback of Martha slips into my bag by mistake. I see a page and fold it back into place, before noticing a small foot of one centimetre is hanging out of the illustration. I prod it dumbly. It kicks back and I hear a cry of 'pull the foot!' so naturally I do. (If somebody in a book is shouting at you it is hard to refuse them.) Out comes Martha, completely 2D and cartoon-like: pigtails and a triangular dress. She starts to run off, muttering to herself 'at last!' but at the door turns to me and says 'remember PaperbackMartha'. I look round the corner and she is gone. I check the twenty-three pages of the book. No sign of her, so I stick her home, her friend Harry and the jam scones in a local library.
That story never did make sense with the main character removed.