Except for the fact that you say the lumps are appearing, disappearing and reappearing, they look like fatty tumors to me. If you can get ahold of it and sort of move it around a little, it's probably a fatty tumor. If it's rock hard, probably not. Definitely email these pix to your vet and keep after her until she's able to see and feel the lumps. We'll say a special prayer for Taz and you that all will be well.