Hi Kathi, Welcome to Yorkie Talk.
It is absolutely heartwarming to hear how much you love your little Abbie, and we all understand that here and feel the same about our pups
Yorkie's coat goes through many changes in the first year or two, so don't worry too much about what you are seeing. The shiny puppy black will be going away and the next layer will be much lighter and the texture will change too, sometimes a bit thinner then filling in again.
I don't think anything a groomer could do in one visit would result in split ends. The lovely "dry heat" you have in Arizona might contribute to her hair condition (I used to live there so know about that
). What is your home grooming routine? What shampoo do you use, how often do you bathe her, do you use conditioner, what kind of brush and how often..... those things will make more of a difference in her coat appearance.
Can't wait to see more photos of her. The tiny one on your profile page is cute. This section of "how to guides" has help for posting photos in threads, and in albums.