Hmm!
Methinks she thinks its a game. my sister had something similar going on with one of her dogs.
she saw a behaviourist etc and this is what worked ..
put her food down and if after 10 mins she hasnt touched it take it away. no treats no fuss. dont even let her think you are bothered.
3-4 hours later try again. same food same bowl. if not touched or unfinished after 10 mins take it away again . put it out of sight and smell. no chews or filled kongs to be given either until she is eating properly, she will eventually eat it. it may take a day or 10 !!
.my sister has a very fussy deerhound she went through this her dog would only eat if hand held food was given to her.
now she eats twice a day from a bowl and her own food, not special chicken etc to entice her. it took a lot of patience and a long time to change her eating patterns, and my sister had to stop stressing over it ( her dog made herself v thin, was seen by vets etc.. she is now bursting with health)
so good luck!!