I would definitely ask about prednisolone. It's a common part of treatments for cancer, might help her feel better. You might also want to ask about ondansetron, which can be given in addition to Cerenia. Cerenia is good for vomiting, but ondansetron is better for nausea. It's a human med. You get the vet to write you a prescription and you fill it at a human pharmacy. Do shop around, pricing varies a lot for it. And make sure you get the generic.
The other thing to ask the vet is if she thinks it's painful, some cancers can be. If so, some pain medicine, like buprenorphine, would help her quality of life.