What a beautiful little girl pup. You sound so happy to have her in your life. With patience, kindness and love over time she will open up and express herself better.
As for the non-eating thing now, have your tried feeding a morsel or two from your hand? Or how about some low sodium beef or chicken broth, something to stimulate her appetite? Will you have her checked at the vet for kennel cough, or did the shelter give you meds? Maybe medication is making her not want to eat. My daughter adopted her dog from the shelter with kennel cough, she was on meds for a week or two.