Grandma stage 4 colon cancer doing home chemo, is the sweat saliva fluid discharge toxic? Pregnant women n kids should avoid contact?

No. From cancer.Org: the only bodily fluid that could be considered 'toxic' would be urine. Men and women should sit to urinate to avoid splash transfer. Saliva and sweat will not have markedly amounts of chemicals. Just love on her as normal!
Not likely. These agents are usually ingested, or given IV (intravenously), so most of the agents are already absorbed, passed through the liver and the rest of the body. There should be little or no problem with sweat, and saliva coming into contact with other people, unless possibly she has a very contagious infection, like a bad cold, bacterial infection, like pneumonia, or specific condition of the drug.
Not to worry. Should not worry. If anything your grandmother should be careful as she is more at risk for getting common infections. Be smart and practice good hygiene.