Glitches by Marissa Meyer.
Lunar Chronicles #0.5
Book Summary: Cinder, a gifted mechanic, is a cyborg. She’s a second-class citizen with a mysterious past, reviled by her stepmother and blamed for her stepsister’s illness. In “Glitches,” a short prequel story to Cinder, we see the results of that illness play out, and the emotional toll that takes on Cinder. Something that may, or may not, be a glitch...
Liana's summary: Cinder is a cyborg now. She realizes everything won't ever be the same as before. Her stepmother is cruel to her, but only kind Peony likes her at all. 'Glitches' is the fabulous prequel of Marissa Meyer's Cinder!
Wow, the fabulousness. I can't believe I didn't find out about this book earlier. It was really short, but the 19 pages is enough to make you cry! It's like, set 5 years before when Cinder is 16, so she's 11. It answers so much questions and it tells you a lot about Cinder's past. I love love love Cinder and I cannot WAIT for book 2, Scarlet! And then books 3-6...I'll be an old maid when the last book of the Lunar Chronicles comes out. </3
Okay, anyways, it's fab. You can find this book online. http://www.tor.com/stories/2011/12/glitches
Once again, it's tor.com to the rescue, letting me read the book I've been wanting to read! Yay.
I love that cover.
Anyways, that is all! I highly recommend you read this before you read CINDER!