Welcome to YT. Yorkie or not she is cute as a button! If how-ever you want a definitive answer about purebred status, that can only be found out through the registration papers and documentation and DNA testing. You run the DNA test on the pup and then compare that DNA test results to the parents DNA. That will tell you definitively if your pup came from these parents who hopefully were registered with a reputable registry.
Alternatively you can get a best "guesstimate" by running a Mars Wisdom Panel test. Although far from 100% accurate, it can be interesting to see what "breed" or breeds of dog your pup has in her.
Enjoy your pup. She looks like a sweetie
