Maryjudy,
I have done all four of the drugs that you mention but not at the same time. The last 3 are known together as FOLFOX. I found this to be a tough regimen. The most common side effect is cold sensitivity. Your sister probably won't be able to eat or drink any cold foods for at least a week after each treatment. She also may have issues touching cold items in the fridge/freezer. My hair thinned a lot but I didn't lose all of it. I had some slight nausea which was controlled by medications.
Avastin isn't a true chemo drug. It is an antiangiogenesis drug which works by blocking the blood supply to tumors. It has very few side effects, but it can cause blood clots or perforated bowel in a very small number of patients.
It sounds like her oncologist is going with a pretty standard approach. Was her colon tumor resected? Did they talk about other potential liver treatments such as resection (6 mets is probably too many to resect right now), RFA (radio frequency ablation, SIRT Spheres, etc. She may not be a candidate for these right nowbut hopefully the chemo will bring her to a place where they can cure her.
Jack