Hello and welcome!! I want to say congrats on adding a yorkie to your family. I don't want to scare you or tell you they are all bad because they aren't but it does matter where and who you have gotten your baby from! I'm no expert but yorkies do have alot of issues that can come up. From bad knee's to collapsed trachea. I didn't know as much about yorkies as I did before and I must say I regret not doing my research now because my yorkie has had her share of problems. I didn't know how delicate they really were. I was blinded by the cute " teacup " yorkies in ads and on tv. I thought they were so cute! Nobody tells you about the health risks involved. My yorkie isn't super small, shes around 4 lbs but to me that is small and I am finding you need to be pretty darn careful with a 4lber even. The smaller you go the more problems you can run into. They can't climb stairs, they can fall from a very low level and hurt themselves very badly. Surgeries are SOO expensive and unexpected things can happen at any time. Of course this is the scary things. As long as you are aware of all the risks, do your research about where your yorkie is coming from. Make sure they have been vet checked and are healthy I say you don't need to worry so much. I wouldn't go for the tinest dog if you are busy and have children, perhaps a little bigger one. THey are very loyal and loving dogs. They are just like little babies which makes them very attached to their owners, they are so full of love with so many kisses and they just want to be on your lap all day, at least mine is that way!
Good luck!