Anyone know the process of peritoneal cancer treatment?

Hello. Its kind of hard to find a clear treatment path and duration online and I was hoping maybe someone could give me some first hand accounts.

My mother was diagnoses with stage for secondary peritoneal cancer. The primary tumor is appendicital. It doesn't seem like a big issue. The peritoneal is the worrying aspect. Her oncologist has been largely positive but I don't really know how much of it is reality and how much of it is just being positive for the sake of being positive.

She started chemotherapy at the end of December/early January. She admittedly did not end up doing the full dosage of chemotherapy right away as she was really struggling with the side effects so they have been gradually increasing her dosage (shes now at 100%). I, honestly am not too sure about the exact chemo drugs used but I know she gets it bi-monthly and that theres one medication administered in the hospital and another she takes home in an intravenously administered bottle.

Anyway, the first couple of scans she has done since the chemotherapy began have shown basically no change. No further spread but also no shrinkage. The doctors seem to believe this is not a negative thing but tbh I am not sure. They seem to want some shrinkage in order to see if they can do the HIPEC procedure on her.

Just recently she experiences ascites and had to have it drained. I know this is a side effect of the cancer. I don't know if it appearing at this stage means its progressed further.

I was hoping someone who has went through this or knows someone who has could let me know how long it took to see results. Just trying to get some answers in this chaotic time.

I appreciate everyone who has read this post. Best health wishes to you all!