Very cute idea, I'm afraid that the jewel won't show due to the hair, but hey who cares, YOU will know it is there and YOU will be able to admire her pretty little toes. I wouldn't think the jewels would pose too much of a choking hazard (too small) and if the glue is safe for human nails, it should be safe for Yorkie nails..... not only that the amount of glue is so small
Go for it, take some pics to share. Who knows, you might be a trens setter!