I didn't want to hog your thread, so I made a new one. Sorry it took so long, my computer has been offline due to weather conditions.
This is Jade's jacket from Petco in a size XXS. You have to surf through all of the clothes to find the tinier ones, but they have a better selection than many places. I read that you don't have a Petco by you, and I'm not sure about ordering them online. I know there are some ladies on eBay that make clothes to your exact measurements. Some of the links have been posted.
This will fit a 4 to 5" neck, 7.5 to 8" chest. It's about 3" in length.
Is this an evil look she's giving me, or what?
Something to compare how tiny the jacket is. It isn't much bigger than a cell phone. If you are ever near a Petco, I'd check them out.