Pancreatitis at Christmas time. That is pretty classic. Is it possible that she got into some (really wrong for dogs) human Christmas food? Or even a bit of fatty meat?
Anyway, that is past now. But it can take the pancreas time to heal after an acute bout of pancreatitis. Some regimes recommend fasting with only water, in order for the healing to take place.
However, yes 10 days is quite a long time for a little dog to go with no nutrients at all. Is she getting any fluids? Are the fluids staying down? If not -then that is an emergency by now. Serious dehydration could set in.
I am sure the vet has provided a diet food....and that is probably kibble. Am I right? Or is it a soft food?
I am sure it is okay, but most likely not anything she can face to eat right now.
Pain and nausea will be what she is feeling, plus a gut that is very very upset and unable to stomach much food.
My feeling is she may be supported temporarily with a liquid nutrient feed. Does your vet know she refuses food all this time? What did he/she suggest? -Apart from the (no doubt kibble) diet food?
If they look baffled when you suggest a liquid nutrient feed, and can they provide one plus syringe (with no needle) for giving it to her.....then they need a brain transplant!
So -if that is the case and they can't come up with some good lateral thinking, you wil have to step in and fix up something for her. Go to the pharmacy and get some plastic syringes without needles. Then go and buy some white fish (not an "oily" fish for now but something plain, some chicken breast, and see if you can get a dietary supplement for dogs powder or capsule/tablet which can be emptied or crushed fine.
Boil and simmer the fish and chicken in some water for a while so the flavour comes out into the water. Drain some of the water off and allow to cool. Put the rest (meat/fish and what remains of the juice) into a blender and whizz it to a soup consistency.
Add the nutrient powder or crushed tablet to the liquid, and to the blended food.
Put the liquid a small amount at a time in the syringe, then gently (a half teaspoonful at a time) syringe it into the gap a dog usually has between the large back teeth and the front teeth. Don't do it too quickly or she won't be able to swallow it. Give her a syringe full every half hour. Make sure it stays down. If it doesn't, then she needs to be in an IV for re-hydration anyway so take her immediately to the vet.
If it does stay down, keep giving her the liquid only for a few hours, then start trying small amounts of the "soup". You may need to thin it down a bit with water if it sticks in the syringe.
See how that goes.