Have you tried Boost, Ensure, etc. Some are vanilla, chocolate, etc .. but there are some fruit flavored as well. I prefer these over ice .. good and cold .. with a straw.
Judy
I know that you would like to see your mom eat more, but I am sure that she is eating what she feels she can tolerate. You do not say much about where she is at but I do know that many chemos will mess up your tase buds or cause a bitter or metallic taste in your mouth, making everything taste yucky. Try popscicles for hydration. I eat those a lot when things taste bad, plus they feel good in your mouth.
Chris
Could you possibly provide a bit more info about your mom and her condition in your profile? Sorry she is struggling, I say give her whatever she wants so long as it can't hurt her.
Try coconut water it comes in the produce section like a juice box it is expensive but it is full of good things like electrolites and potassium. I also tolerated "naked" juice the one with watermelon and a touch of mint. Yougurt with salt on toast was also good to me. I hope you both get some relief soon.