The choices made by the previous owners is one thing but I need to first comment on the airlines.
I just cannot imagine any airline allowing a pup of this size to travel such a long (possiby hot) day like she did. I am surprised she wasn't in worse condition when you got her.

Oh, just bless her Yorkie puppy little heart!!
WOW - She really had an angel with her during this flight. Bless you for taking her in.
Now, back to the previous owners. Shame on them!!!