My yorkie chichuahua mix is very similar to the above description.
She is super smart and extremely loyal. She loves to fetch and chew anything that squeeks. She gets hyper spurts and runs laps around the house and then will collapse to rest.
Beware: she has seasonal allergies! She also suffers from “reverse sneezing” attacks- if this happens just calm the dog down and massage their throat or neck. It should only last for a few second but sounds like they are choking to death.
On a last note: be SURE to get all female dogs spayed. I did not and Poor Lucy suffered from Pyometra and had to have an emergency spay that she almost did not survive. The surgery was extremely stressful and expensive and could have been avoided completely by my vet telling me to have her spayed as a puppy.
I love my dog and have never been an animal lover. She is the sweetest thing and my absolute best investment in time and money.