You need to ask your vet about this, but in my limited (one data point) experience, your GiGi may not be able to tolerate chemo. At this point, offer her any kind of food she'll eat; the rules about tuna, etc. don't apply.

GiGi, Smokey would advise you to be a good girl and take your pills. Less stress on you and your meowmie can't hurt!