[YorkieMother]

She is a normal puppy doing normal things and the world is a very intersting place to be in and it wonderful to explore.
Just start with the basics and work through everything calm and relaxed. She not bring tough on you out of being spitful or wanting to be in charge, she just being a good healthy normal puppy.
When she first came home you were the world and the best thing ever.. As the world expands it more intrusting then you are and off she goes to see it.

One way to train this is on a long line call her to you by using her name, not come and help gently gather in the leash once she gets to you treat her for coming... yes I know you helped that not the point of this and then release her back to sniff or play.
Do it over and over in a 15 minute session and then head in side.
What you are trying to do is teach her that if she comes you are great in a calm manner with the treat and then letting her go also not a block to having what she thinks she wants.
What will happen is that the more you say go sniff the less she will want to go sniff. It becomes ok to do not something to be snuck or not allowed.

Working come as in come here right now is a different thing and come or here should only be used when a come is going o happen. If sniffing or ignoring happens go get the dog.
Do not chase just calmly go get.
Right now she is seeing you as a stop or black to all things great in the world. you need to switch that up.

As for puppies going through stages yes they do... but teeenage hood and other stages if you forget that dogs do not genralize ( so sit in the livingroom and sit in the bedroom and sit out side are not the same) makes them look far more stubron or rude then they really are.
Also they are learning a great deal and things can fall apart when it goes from being something learned to a know thing.. so from short term to long term memory... just like kids as well when tired the last thing learned is the first thing they forget.

JL