Always leave food and water for your puppy. He or she should never go without. Yorkies blood sugar can drop rapidly without food. This is very important for the first 12 weeks.
My Sadie ate small meals all the time as a pup and we never had a problem with her blood sugar getting to low. But I have heard horrible stories of puppies that were left alone or without enough food. You can end up at the vet or even some have lost a puppy. Also, keep some nutrical (vitamin paste from pet store) on hand in case your pup needs a boost. It has saved lives.
SO, are there any pictures of your little pup for us to see?
We love puppies and love to see pictures of them as they grow.