RebeccaG has a little puppy named Ksena that looks a lot like yours. She had a thread titled much the same when she got hers. We all speculated it was a chi mix. She did DNA testing that was sort of inconclusive. I think it may be that a chi was used way back in the breeding. At one time unscrupulous breeders did this to try to get the size to stay small. Yours was probably from yorkie parents but somewhere way back there may have been some funny stuff in the wood pile.
I will bet she is just as loving as can be though!
I could not find the other lady's original thread where she questioned whether she was all yorkie but here is a follow up saying she thinks she is getting cuter:
http://www.yorkietalk.com/forums/con...mama-eyes.html