There is a discussion of "floating ribs" here:
http://www.yorkietalk.com/forums/yor...ween-ribs.html
Every Yorkie has a pair of floating ribs, which can sometimes protrude a little and look funny, but it is normal and harmless. Is your Yorkie in any pain? If you have any doubts, take her in to see the vet, and let us know what it turns out to be.