I am so sorry she is dealing with this.
Food is such a personal thing that even stuff that "works" may not be palatable to a chemo patient.
If she likes soup, you could try a chicken broth based soup with an egg-drop theme to give her some protein.
If she likes nut butters but is simply having a hard time swallowing it, you can add it into a smoothie and thin out with water or milk or juice or whatever she prefers till it is a consistency she can manage.
Not sure how appetizing blender-meat would be, but it is an option. You can thin it out with broth and make a sort of soup of it; more like a thicker broth then....and served in a bowl not glass may make it more eye-appealing.
Milk shakes if she has no objection to dairy. Yogurts and puddings fall into this category too, if she likes any of that.
Souffle type foods may be a special treat, but of course, work to make.
I'll post a few more in a bit.
Thoreau said, 'A man is rich in proportion to the things he can leave alone.'