Nutmeg's swollen face worsens

Really quite worried about Nutmeg. Her face is swollen on both sides, but unevenly. There seems to be a bump on top of her head, to her left side and she also appears to have a slight bump on the left side of her neck (from her perspective, if looking at her front on it is to the right).

I took her to the vet on Friday 7th. I don't have a poultry specialist vet and my vet practice had just, this week, been taken over by a new couple of vets. What the vet said matched what I'd read. Poss Myco and prescribed Tylan.

However today is day 4 and still no improvement. What could it be?