Is it safe for me to give oral sex to woman who is on chemo?

Probably. Loving someone while going through chemo is an important part of being alive, feeling hope, and feeling whole. Check with her doctor. When there are concerns about friction/injury or a partner's white blood counts being low, they might recommend using a barrier method like a dam: https://www.Optionsforsexualhealth.Org/sexual-health/sexually-transmitted-infections/barriers/oral-dams.