A quick fix for a small cold dog is to find an old jumper (sweater) Mens are usually a good fit. See if the cuff of one sleeve fits over her head and is not too tight around the neck. Cut off the sleeve. Measure it up against her, mark where the front legs go, snip a hole for the legs, put it back on the dog and trim the length to fit. You can then oversew or bind the leg holes and the bit you cut off the back. One old jumper makes two instant coats and you can use the leftover bit for another kind of pattern.