I interviewed a dog behaviorist yesterday (for an article on adding a second dog to your home) and she said to take away all the toys at first. This will lessen conflict.
You can then gradually give the dogs the toys - starting with the least interesting toys. If they are fine with those, you can give them more toys and so forth.
According to the behaviorist, your 1 year old will establish her own boundaries with the new pup. So, if the pup goes near her and she growls, don't be angry with either of them. Your older yorkie is just teaching the other one what is appropriate behavior.
She is emphatic that the dogs need to be taken for walks together to let them know that they are friends (she says that you don't go for a walk with your enemies
). Also, take each of them out on their own once in a while. This helps them understand that they are still individually special to you as well as give them a breather from the other one.
So, take the pup to socialization classes - this gives you time alone, trains and socializes the puppy. Definitely a must!
Good luck.