Welcome to YT!! This is a wonderful place for yorkie owners & we have so much addictive fun here, I hope you will be back as you prepare for your own furbaby & let us see pictures when you get him or her.
I don't think what this breeder is asking is all that unusual. There are a lot of just curious people out there & unfortunately scammers - it sounds like she is just being wise and careful. Once you go to her home, you will have a better feel for her and her dogs and if this is where you want to buy from. Best wishes.